Student Question: I still do not understand why B is the correct answer choice but not D. The stimulus says 'cannot afford any reductions' and therefore concludes that they should pass laws to make it more difficult for overseas investors to remove capital. My understanding is as long as the total capital does not decrease, it should be fine. But B says 'will not invest additional', which seems to be consistent with 'the current total does not decrease'.

Tutor Answer: Thanks for your question! The key here is noticing what the actual necessary condition for sustaining the economy is: not "the current total does not decrease/no reductions" per se, but actually "as much capital as possible from overseas investors." "As much capital as possible" is the actual bar we need to meet (sustain economy --> as much capital as possible); "cannot afford any reduction" is a inference built on that initial statement: we need as much capital as possible, therefore we cannot afford any reduction. You could almost think of this sentence as giving us a necessary condition for the necessary condition in sentence one (as much capital as possible --> /reduction in capital).

But the conclusion assumes that taking steps to ensure the second condition (/reduction in capital) will therefore ensure the first necessary condition (as much capital as possible, which is what we're really interested in) and so meet the necessary condition for sustaining the economy. This doesn't have to be true: /reducing capital is not the same thing as "as much capital as possible," and B makes it clear that taking these kinds of steps to avoid reducing capital will likely fail to ensure "as much capital as possible." That's why B would weaken. D focuses only on the second condition -- reduction vs. no reduction -- which isn't as central to our conclusion as the key assumption of "/reduction --> as much capital as possible."

Student Question: Can someone please explain E? I do not understand how it is supported by the end of the third paragraph.

Tutor Answer: Thanks for your question! Paragraph 3 starts by giving us a critique of Sibley's work based on DNA-DNA hybridization: the critic is complaining not about the DNA data about genetic differences, but about Sibley's interpretation of those differences. The paragraph then says that Sibley would agree in some ways with this critique, and gives us a quote where Sibley says that our decision to "recognize" certain genetic differences is a practical and limited one, because there are "all degrees of genetic differences between populations of organisms." Thus, the concept of a species is "slippery" because we are trying to apply a limited conceptual system (our "set of definitions and names") to data that Sibley says is complex and doesn't always fit our conceptual framework.

All this supports the idea that even if we have more accurate data -- i.e., even if DNA-DNA hybridization and similar techniques are refined -- that data will just give us a clearer picture of how complex these differences are: but we will still have to make a decision on how to categorize those differences, which is where Sibley says the "slipperiness" comes in. So we have reason to believe that Sibley would agree with E: that even if these techniques are refined, disagreements about species classification are likely to persist. The problem isn't the data, but our limited tools for classification.

Student Question: Can someone explain how to handle response questions? I understand it should strengthen the view of the respondent, but what is the difference between a strengthen question and a response question?

Tutor Answer: Thanks for your question! What makes this sort of question different from a general "strengthen" question is that, in a comparative passage context like this one, the correct answer to a response question not only wants to support/defend/maintain one passage's point of view, but needs to respond to the point of view of the other passage. In other words, unlike a strengthen question, where the correct answer choice will relate to only one argument in a particular way, the correct answer on this kind of question will have to relate to two arguments. I wouldn't necessarily say it has to "strengthen" one and "weaken" the other, because the two points of view will not always be contrary to each other: but it does need to represent one passage's point of view in response to something said in the other passage.

Student Question: Can someone please explain C? I did look at the second point in passage B which concerns the 'commercial exploitation', but was hesitant to choose C because I could not see how the 'commercial exploitation' can be understood to draw a distinction between monetary value and nonmonetary value.

Tutor Answer: Thanks for your question! You're looking at the right phrase here: but keep in mind that we don't need just one single phrase to make the distinction that C mentions. We just need that distinction to be important in the passage as a whole. So even though "commercial exploitation for trade, sale, etc." refers only to monetary value, the fact that we're told that such exploitation is "incompatible" with the protection of UCH does make that distinction, by telling us that we are protecting UCH for other, nonmonetary reasons, as the other points also imply.

Student Question: If an answer choice were to say: one’s sense of approval of one’s character and project does not increase material well-being (flipping answer choice E), would that count as a necessary assumption?

Tutor Answer: Thanks for your question! Notice that "material well-being" is not part of the fundamental logical structure of the stimulus: the phrase that mentions material well-being ("where the good life is understood not as a life of material well-being, but as a morally virtuous life"), while it clarifies what we're talking about, doesn't add any new conditions to the stimulus. It's not ruling out "material well-being" as "not allowed" from the good life. So saying that "one's sense of approval of one's character or project does not increase material well-being" could be true, or it could not be true, and it wouldn't affect the argument: if we negate it to "one's sense of approval... does increase material well-being," the argument could still hold.

Student Question: So is the assumption that there is no advantage to the physical crashes over the simulated crashes that would outweigh the higher costs. Or, as said in the video, is there no advantage to the physical crashes over the simulated crashes outside the concern of “safety issues”? Then, I remember learning that if a conclusion is hypothetical, we are already considering that world that is presented by the sufficient condition - is that another reason why answers like B and C just do not help strengthen the reasoning?

Tutor Answer: Thanks for your question! I think both assumptions are accurate: that physical crashes don't offer advantages beyond "safety issues," and that those advantages (if there are any) don't outweigh the cost advantages of simulated crashes. While you're right about how we deal with hypothetical conclusions, the bigger problem with B and C is that neither addresses the assumptions you flagged.

Student Question: The explanation of D says that it does not explain why people would be okay with not getting a minimum amount, and the explanation then goes on to specify that this is the minimum amount or lower. But why would D not also suggest that people would would agree that everyone in their position would need to get an amount of primary goods greater than the minimum?

Tutor Answer: Thanks for your question! The key here is the phrasing in the passage: "should get at least a minimum amount of primary goods." The phrasing here isn't so much about the actual amount that people think is enough for themselves: it's about the limit, or the lower bound, on what they would consider enough for everyone. The "at least x" position can include people who thinks they should get more than x. Thus, if I believe everyone should get 2 slices of pizza, but there are a few people at the party who believe everyone should get only 1 slice of pizza, then we can all agree with the position that everyone should get at least 1 slice of pizza: even if most people, like myself, think everyone should get at least 2 pieces of pizza to not be hungry. So even though the sentence here mentions a lower bound, that doesn't mean the people in the original position are necessarily saying everyone should get only a minimum amount: it just means that everyone would agree that no one should get less than the minimum.

Student Question: I get that C is a sufficient assumption but I feel like it would only be sufficient if you assume that just because the police didn’t find any footprints, that means there were no footprints...is that a reasonable assumption to make?

Tutor Answer: Thanks for your question! You're right that we need to know something about the police finding footprints: but the stimulus already gives us specific rules about this. When a stimulus gives us conditional rules like this, we can take them as descriptions of fact: if Herbert had committed the murder, then we know that the police would have found either his fingerprints or his footprints. If Samantha had committed the murder, then she wouldn't have left either (so the police wouldn't have found them). So if Herbert and Samantha are our only two options, then we're already "covered" when it comes to knowing whether the police will find fingerprints/footprints that are there. But that's the assumption: if someone else is a potential option, then we don't know for sure what sort of evidence they would have left behind, and whether the police would have found it. So the assumption "only Samantha and Herbert" gets rid of the need to make additional assumptions about finding footprints, because then we can just fall back on the given conditional rules.

Student Question: Hi! For some reason, the explanation video for this question skips over E, and I am confused how that is the wrong AC. Can you help please?

Tutor Answer: Thanks for your question! One way to think about main point questions in RC is that they will act as summaries of the argument in the passage: in other words, every major part of the argument will typically be represented in the answer choice, which often means every paragraph in the passage will be included in the summary. So even if an answer choice is descriptively accurate about something going on in the passage, but that description applies only to one paragraph, it won't work. That's why E isn't right: the only paragraph you might be able to look at to "explain the chemical processes that make a particular new product a promising alternative to an existing product" would be paragraph 2, and even that paragraph doesn't really explain the processes in much depth, beyond telling us what they are. So A, which takes in the whole passage more broadly, is a much better answer.

Student Question: I do not get why I'm supposed to assume that environmental pollution increases one's incidence of cancer. I try to eliminate all my preconceived notions/knowledge on this test, but questions like these make me feel like that isn't a uniform rule. I thought E could be correct and weaken the argument because the statements explaining the incidences of cancer and fat intake relate to the general pop of a country, not an individual; but, the argument is speaking only about individuals. How I interpreted it is that: an individual with a low fat intake should not necessarily reduce their normal fat intake to reduce their risk of cancer, as they may experience adverse effects from lowering a fat amount that was appropriate or even low to begin with.

Tutor Answer: Thanks for your question! Remember that on weakening questions, we want to weaken the relationship between the premises and the conclusion. In some ways, that premise-conclusion relationship defines the target we are trying to attack: if an answer choice fails to hit that target, even if it seems like it would independently work against the conclusion, that will typically not be our answer. So to start with, let's define our target: remember that the premise here is a statement about correlation between cancer rates and fat intake in a country, and the conclusion makes a statement about individuals wanting to reduce cancer risk. If we want to talk about the relationship between the premise and the conclusion, it's basically an application of the fat-intake/cancer correlation at the national level to individuals.

In short, our target to weaken is the "country rates --> individual risks" relationship. There are plenty of angles we could take to attack this: we could question the assumption of causation from correlation (fat intake is causally related to cancer); we could point out some additional factor that differentiates high fat-intake countries from low fat-intake countries, etc. But notice that E doesn't attack this relationship. You're right that we might be able to interpret E as undermining the conclusion, if we interpret the conclusion as being a blanket statement: "Every single individual who ever wants to reduce cancer risk should reduce fat intake." But even taking that interpretation -- which doesn't necessarily seem obvious; we don't know that the individuals described in E are necessarily those who will want to lower cancer risk -- we would be attempting to independently weaken the conclusion. We wouldn't be adding information that makes the argumentation itself from the stimulus seem weaker, as D does.

Finally, to your question about outside knowledge: when we say we don't want to rely on outside knowledge on this test, what that means is that we don't want to allow outside knowledge to obscure our view of the logical relationships/structures on this test. This doesn't mean we set aside all of what might be considered "common sense" knowledge. This is especially important for causal reasoning, where many question types rely on bringing in additional information to weaken/strengthen/expose a flaw in an argument: think how many answer choices might rely on some basic assumption like "exercise is healthy." If we weren't allowed to bring in any real-world knowledge from beyond the stimulus, then the whole approach of weakening by proposing an alternative hypothesis wouldn't work. If you find this hard to buy for this question, instead of "environmental pollution" in answer choice D, imagine it just said "potential alternative cause." The point on this question is less the content of AC D (you could substitute "environmental pollution" for "exposure to radiation" or "low rates of exercise") as what it does: provides an alternative explanation that undermines the correlation --> causation assumption in the stimulus.

Student Question: I do not understand why B) is correct. Specifically, I am having trouble understanding the meaning of “does not have to be indifferent”. How else can you phrase “does not have to be” in this context? Or how can we reword answer choice B?

Tutor Answer: Thanks for your question! I think the easiest way to understand B is to first use the negation test on it: remember that a required assumption will destroy the argument if negated. If we negate B, we get "A novel that poetically condenses a major emotional crisis does have to be [i.e., must] be indifferent to the important moral questions raised by that crisis." This is a clear conditional (condense --> indifferent), and would destroy the argument. Thus, B is a necessary assumption.

To understand what B says in its original form, let's imagine "re-negating" this conditional. Remember that you negate a conditional statement A --> B simply by saying A AND /B (in other words, you can have A without B, or A can exist alongside /B; you disprove "all swans are white" by showing one swan that is not white). So by re-negating condense --> indifferent, you're saying that it is possible for a novel to poetically condense a major emotional crisis and not be indifferent to the moral questions raised by the crisis, which -- though it sounds weak -- is clearly a necessary assumption for this stimulus. If this is not possible, then the argument falls apart.

Student Question: How do we know it is “impossible” to confirm for E? What if we get good data dating back all the way to the Mayan civilization? Also, can you please explain D better? Intuitively, I’m having trouble seeing how a flaw does not destroy using an activity?

Tutor Answer: Thanks for your question! You're right that the passage never says outright that it is "impossible" to confirm the accuracy of the reconstruction. This is more of an implication from the last paragraph, where the author says that "a hypothesis can be tested only against the best available data" -- the author is speaking generally here, and seems to imply that the fact that any hypothesis relies "only" on the best data available is a limitation of some sort. But you're right that the phrase "impossible" doesn't show up. This is a case where we take the question stem literally, and look for a statement the author would "most likely" agree with: since the other answer choices don't work with the passage, even though "impossible" is not necessarily implied by the passage, it's certainly not ruled out, either. So E is the best answer.

The reason D doesn't work is because, although the author does say reliance on the best available archaeological evidence is a flaw, this doesn't mean archaeological evidence is an inappropriate source of historical data. In fact, the first sentence of the second paragraph suggests that the author thinks archaeological evidence actually is an appropriate source of evidence: "Lowe sets forth a plausible explanation of the collapse that accommodates the available archaeological evidence." Accommodating archaeological evidence seems to be a feature making this argument "plausible." It's actually quite consistent to call something flawed, and yet still believe it's appropriate to use, often because it's the best available option. Imagine someone saying that democracy is flawed, but it's the best system of government we have, or that there are problems with airplane travel, but it's still the most convenient way of getting from place to place.

Student Question: (C) didn't look good because the stimulus didn't clearly show how certain human concerns and interests arise in all of the world's cultures. In your explanation, you noted that "storytelling seems to be common to all cultures" - why is that? Is it because of how it appears to be "a universal aspect of both past and present cultures"? And if so, doesn't "universal" describe "aspect" and not "culture"? Isn't this sentence compatible with a situation where storytelling is a universal aspect of most but not all past and present cultures?

Tutor Answer: Thanks for your question! To your question about the word "universal," the word "universal" describes something that shows up everywhere/in all situations. So to say something is a "universal aspect" of past and present cultures would just mean that it shows up in all past and present cultures.

That said, the word "universal" isn't part of our support for this question, since it's in the first sentence, which is the conclusion of the argument. The question stem asks about the second sentence, which, as you pointed out, doesn't necessarily state that comparative study has looked at all cultures. So you're absolutely right that C doesn't have to be true -- but it is still the most supported. The other answer choices all bring up elements that aren't addressed in the stimulus; while C goes a little further than the stimulus necessarily does, the stimulus at least gives some support for this answer choice. Imagine looking at the skeletons of several unrelated types of reptiles, noticing a common bone structure, and concluding that all reptiles have that structure: it might be a hypothesis that could be readily disproved, but it would at least have some support.

I hope this helps! Remember that on Most Strongly Supported questions, we'll be dealing with various degrees of support.

Student Question: I wonder if someone could further explain E? The stimulus says 'a low-protein diet with an abundance of fruits and vegetables and a minimum quantity of meat and dairy products'. E says 'strict vegetarians', which I understand as no meat. Does the word 'minimum' include 0?

Tutor Answer: Thanks for your question! Yes, while the meaning of the word in other questions might depend on context, "minimum" generally means the "lowest possible," with no lower bound necessarily. So zero meat products would certainly satisfy "minimum meat."

(If the minimum to zero equivalence is still bothering you, keep in mind that for all we know, these strict vegetarians might take in some dairy products, too, so it might not be a complete "zero.") If the stimulus meant "a small amount, but not none," we would expect that to be stated more directly. I hope this helps!

Student Question: I have a side question regarding B. I understand that the latter part ('something that necessarily results from that action' refers to a causal effect'), but can it also refer to a necessary condition? For example, if given a conditional: rain -> cold, the coldness can both be a necessary condition to the rain and an effect brought by the rain.

Tutor Answer: Thanks for your question! I would differentiate between the two phrases "something that necessarily results from that action" and "necessary condition for something to occur" (I added "for something to occur" because, without getting too much into the weeds, these are two causal ideas that, when we think about strictly conditional logic, we might both call a "necessary condition"). You're right that without additional context, rain --> cold could mean "whenever it rains, it gets cold: or "being cold (beforehand) is necessary for rain to occur." It could mean both, as you said, (although we would then assume that it gets colder after rain, since it was already cold before rain), or it could mean only one: we would need context to figure it out.

In most cases, the arrow will probably mean either the result or the condition for occurrence: humans need water to survive (survive --> water) means water is a necessary condition for survival, not a necessary result of survival; whenever I swim, I become happy (swim --> happy) means "happy" is a necessary result of "swim," not a condition for swimming to occur. Remember that in the end, diagramming is a form of shorthand; to properly interpret a conditional statement in terms of causation/chronology, we need additional context.

Student Question: Hello, I wonder if someone could explain D? I got it right by POE but do not understand how the last sentence supports D. I just do not understand what the last sentence means. Thank you!

Tutor Answer: Thanks for your question! You're right that the last sentence is a bit dense. Before we unpack it, let's make sure we understand the structure of the last paragraph as a whole.

Remember that we ended paragraph 2 with the author raising a potential challenge to Bordwell's thesis about the "classical style," which Bordwell defines in terms of realism (paragraph 1). In paragraph 2, the author mentions musical films as a potential exception to the rule of "realism." At the start of paragraph 3, we get Bordwell's response to this challenge: that the musical's conventions "cue viewers to expect a different structure... from that of other genres, a structure that audiences are prepared for and thus accept as 'realistic.'" The author questions this response, and we end with the final sentence: "Because knowledge of genre is acquired, it would be worthwhile for scholars like Bordwell to first consider how viewers process cinematic images and eventually come to accept them as conventions before generalizing about the realism of certain film styles."

When we say knowledge of something is acquired, we mean it is learned over time -- i.e., not something automatic or inherent. What the author is saying, then, is that audiences learn to recognize the elements of movie genres over time, not automatically, and that Bordwell should take this fact into account before defining what counts as "realism." Reinforcing this point, the sentence also says viewers come to accept cinematic images as conventions only "eventually," not right away. Both these points about "acquired" knowledge/accepting images as conventions only "eventually" support answer choice D.

Student Question: I thought the correct answer had to include both the fact that the side effects are not well understood and it requires altering an important resource. How come B is correct? I thought both B and D sounded incorrect because they both lacked one of the two facts.

Tutor Answer: Thanks for your question! You're right that D doesn't mention the side effects, so it doesn't work. B does mention both facts: it mentions altering an important resource, and it also mentions the side effects not being understood when it says "the consequences are not adequately understood." The side effects would fall under the umbrella of "consequences."

Student Question: I interpreted E as saying that in one community, everyone has uniform linguistic practices, but when you compare community with community, there are large differences. Based on that, I thought it would strengthen. I do not understand how this sentence could be interpreted to say that even though there are these differences between communities, the communities have uniform practices, especially since it says “within” these communities. Thanks!

Tutor Answer: Thanks for your question! You're right that E is phrased somewhat ambiguously. My inclination on the surface reading would be to understand E as saying that linguistic practices are uniform across communities: I can see your point about the "within," but the "despite" seems to suggest that we're looking for something different than we'd expect, given that there are large differences between the communities. That seems to suggest that the practices are uniform across each of these communities -- but that's definitely not made super clear, and I can see how you got to your reading too.

I think the more important point is that either way, the relationship between E and the particular claim we're interested in strengthening isn't especially clear: "In the end it must be acknowledged that the laws governing the transformation of language are not like the laws of physics. Language usage depends on choices made by individuals, who are subject to persuasion." In a sense, I guess your reading might strengthen the second sentence by implying that certain individuals within each of these communities were persuaded in different ways -- but that seems fairly implicit (what if the communities themselves, in some way, choose how to use language, as opposed to individuals making choices?). Compare this to answer choice B, which clearly shows individuals (the students) sticking to the language usage they were taught, and hopefully you'll see how B strengthens more directly.

Student Question: I cannot understand how the first sentence is not at least a sub conclusion, since it is given support by other statements in the premises. In addition, how does that first sentence in any way support the last sentence? There is little to no relationship between them or support, without the middle sentences.

Tutor Answer: Thanks for your question! You're right that this is a tricky question: I would actually agree with you that the first sentence looks like a sub-conclusion, since we do have some evidence (the reference to Billie Holliday) backing it up. But that doesn't conflict with the right answer: "a statement for which some evidence is provided and which in turn is used to provide support for the argument's main conclusion," as C says, is a perfectly accurate description of what the LSAT might elsewhere call a sub-conclusion.

And you're right that on its own, the first sentence doesn't support all of the last sentence. It does support part of it, though: it gives us support for "hornlike voices," whereas the third sentence gives us support for "voicelike horns." It might help to think of the argument as (claim 1 about voices + evidence) + claim 2 about horns --> conclusion about voices and horns.

Student Question: I’m confused on how the answer choice is E. How can we assume that the second project takes a higher priority than the first?

Tutor Answer: Thanks for your question! An important point to keep in mind is that "not higher" doesn't necessarily mean "lower," just as "not more" doesn't automatically mean "less" (it means "equal to or less"). So when we look at E and say that project 1 doesn't have higher priority than project 2, this doesn't mean that project 2 has higher priority than project 1. They could have equal priority, which is in fact what the stimulus tells us: the two projects are "equally important." So their objective priority levels are the same, and the differentiating feature is the deadline. I hope this helps!

Student Question: I interpreted E to say that certain items found in the pits were discarded by a DIFFERENT group of people. I thought “Certain types of items were never discarded by members of this group of people. “ could perfectly well mean that certain items were actually discarded by members of other groups of people, meaning that whatever IS left, assuming it's not subject to erosion, etc., cannot necessarily tell us a lot about the people who lived there since it's not guaranteed that we’ll be able to pinpoint which group threw out which item.

Tutor Answer: Thanks for reaching out! While I can see how you got to that reading of E, that reading would be much more supported if the answer choice said "Certain types of items found in the pit were never discarded by members of this group of people," which would then open up the question of how those items got into the pit, and the possibility that other people threw things into those pits. But as the answer choice is currently phrased, another possible reading is just that these people never threw away certain types of items -- perhaps they burned them, or passed them down to their descendants, etc. But this only tells us that some things are not in the pit; it doesn't necessarily mean that what is in the pit doesn't give us useful information -- so this doesn't really strengthen the archaeologist's point. Even taking your reading, having some other people's belongings in the pit still leaves open the possibility that we have plenty of valuable material in there (there could just be a little bit of other people's stuff in the way -- we don't have any information about quantity, etc), so this wouldn't really strengthen the argument either.

Student Question: Does changing the quantifier from “all” to “some” in answer choice C make it correct? I’m diagramming it out but must be missing an inference.

Tutor Answer: Thanks for your question! C tries to reason from "reasonable beliefs" (or the subset of "reasonable beliefs" that intersects with "no observable evidence") and conclude whether or not those beliefs are based on information from a reliable source. If you look at the conditional rule established in the stimulus ("If a belief is based on information from a reliable source, then it is reasonable to maintain that belief," or reliable source --> reasonable), you'll see that this is a sufficiency-necessity confusion. It wouldn't be fixed even if we only said "some" rather than "all," because we have no way of knowing for sure if the subset of "reasonable beliefs without observational evidence" overlaps at all with the set of "beliefs based on a reliable source."

Student Question: How do I know that the “thus” sentence at the end, is not a conclusion indicator in this stimulus?

Tutor Answer: Great question! You want to be careful with indicators like "thus" and "therefore," which typically indicate a conclusion, but not necessarily the main conclusion. We can differentiate by looking for other indicator words and phrases that show us the logical structure of the argument: in this case, we have a "for example" that starts the entire discussion of plankton. When we give an example, we're usually trying to support another statement, so we know that the point of the whole plankton section is to support something else, in this case the actual main conclusion ("this characteristic is actually quite common"). Since that whole section is "bracketed off" as support, we know that the final sentence, starting with "thus," might be a conclusion for that section, but is not the main conclusion of the argument. This isn't the only question where this "thus" within a "for example" structure shows up, so it's good to look out for it.

Student Question: Since the discovery that the identified radioactive substance was barium led to Meitner’s breakthrough, and since it was also established it was sitting there for a couple years, shouldn’t (E) be correct? E seems like a more accurate description of what (A) is describing. If you can explain why this isn’t correct, I'd appreciate it.

Tutor Answer: Thanks for your question! Remember that we are looking for evidence that is relevant to "corroborate the findings" of Meitner and Frisch's paper -- i.e., relevant to support the nuclear fission hypothesis. The trouble with E is that the fact that radioactive products of neutron bombardment of uranium went unidentified for so long is not itself the evidence needed to prove nuclear fission: the evidence is the experimental results. Imagine a detective concluding that a criminal is guilty after finding their fingerprint somewhere no one else had looked for it: the relevant evidence for the detective's conclusion is the fingerprint itself, not the fact that no one found that fingerprint for a long time (even if that fact is true). The key here is staying close to the context of the last sentence, and being clear on what "relevant evidence" refers to.

Student Question: I wonder if someone could explain A? I know D is a better answer but does Yi-Fu Tuan's argument undermine the common view by introducing an alternative explanation, like what we usually do in LR weakening questions?

Tutor Answer: Thanks for your question! While you're right that introducing an alternative hypothesis can weaken an argument, this presupposes that the alternative hypothesis is known to be true, whereas the original hypothesis is not (remember that the Weakening question stem usually starts, "which of the following, if true..."). In this passage, meanwhile, both hypotheses are somewhat tentative/still on the table -- and the author's own hypothesis doesn't even show up in the paragraph we're interested in for this question. Keep in mind also that an alternative hypothesis weakens more if it is mutually exclusive with the original hypothesis: in this case, even though the author seems a bit skeptical of the resource procurement model, we don't know that Yi-Fu Tuan's insight is incompatible with that model, or definitely rules it out (the author ultimately applies the new hypothesis to "some" clearings, not necessarily all clearings). Finally, since this is a primary purpose question, remember that the logical effect of introducing this new hypothesis is not necessarily the same thing as what the author intends to do by introducing this hypothesis. Even if this new hypothesis could, logically speaking, weaken the original hypothesis, we figure out what the author's purpose is from context clues: Yi-Fu Tuan's insight comes immediately after a sentence that suggests an alternative hypothesis, which the author then proceeds to develop, suggesting that we've moved on now to building the author's own argument. Even if this insight could weaken the resource-procurement model, that's different from saying the author is primarily using it to undermine that model.