This is a Necessary Assumption question. This is a classic NA stem, and we know it’s NA because the question stem is asking for an assumption the argument depends on.
Proponents of organic farming claim something. What do they claim? Chemicals used in farming harm wildlife. Makes sense. What about it? Well, this next sentence looks like a counter-point. If we’re going to stop using chemical fertilizers and still produce the same amount of food, we’re going to have to farm more land than we currently farm. That makes sense: We don’t use chemicals for the fun of it. We use them because they dramatically increase yields. So if we stop using them, the same amount of land will produce less food. Therefore, we’ll have to farm more land to produce the same amount of food. The final line looks like the conclusion: Organic farming destroys wildlife habitat.
Well, this may seem like a somewhat reasonable argument. It may not be immediately clear to us why it isn’t valid. That’s okay though. The answer choices will feed us the prompt that will help us resolve this. We want to approach NA questions by keeping an open mind, considering what each AC suggests, and using POE to navigate through.
Answer Choice (A) This doesn’t have to be true, but it’s interesting how this is constructed. This may seem to contradict a premise, but it actually doesn’t. The first line doesn’t say that these chemicals harm wildlife. It says that organic farming proponents claim that they do. So this answer is telling us that the proponents’ claims are true. But they don’t have to be. Even if these chemicals are perfectly safe, their absence will still decrease yields and increase need for more land devoted to farming.
Answer Choice (B) This is similar to A. I’m not sure that the chemicals’ effects on wildlife, if any, actually matters. The conclusion is only addressing the effects of needing to use more land for organic farming. The chemicals don’t need to be harmful for these effects to follow from the greater land usage of organic farming. This diminishes the benefits of organic farming, but it doesn’t impact the downsides which our conclusion is solely concerned with.
Answer Choice (C) This is the same issue as A and B. Seeing a third answer choice in a row miss the point in the exact same way makes me a little cautious though. I’m not going to change course until I finish the remaining answer choices, but I am prepared to reevaluate the stimulus if this continues. The LSAT is not normally so kind as to allow us to eliminate three answer choices all for the same reason. We accept the kindness when offered, but beware test writers bearing gifts.
Answer Choice (D) This doesn’t have to be true, but it’s at least moving in a different direction from A, B, and C. And I can see why it might be attractive. If we plant different crops, maybe we can increase yields that way. By switching from a lower yield crop farmed non-organically to a higher yield crop farmed organically, maybe we can balance our yields that way without having to devote more land to farming. That makes sense and might be a possibility, but does this have to be true? No. They don’t have to be the same crop to result in lower yields. Different crops can still get us to the same result. This is an interesting suggestion, but it doesn’t check out.
Correct Answer Choice (E) Oh, this makes sense. I definitely was not going to predict this, but it totally works. I’ve been assuming that there can’t be any overlap in land use: It is used for farming or as habitat but not both. But there is nothing that says it can’t be both. If organic farming uses land in a way that preserves it as habitat, it can have multiple functions and serve as both farm land and wildlife habitat. In this scenario, greater land use would not necessarily result in the reduction of habitat. Many shade-grown coffee farming practices have this effect. The coffee plants are allowed to grow beneath and along side other trees which preserves habitat for birds.
This is a Necessary Assumption question. We know because the question stem is asking for an assumption the argument depends on.
The amaryllis plant goes dormant when its soil dries up. That seems like a handy trick and is probably an important adaptation. So, what about it? Oh. It looks like we’re jumping straight into a conclusion. If we’re keeping these as house plants and want them to really thrive, we should withhold water to mimic its natural habitat by creating a dry season for it. Well, I create dry seasons for my house plants sometimes, but they don’t particularly thrive from it. It might actually be nice to have a plant that has an evolutionary adaptation to negligent house plant owners.
This is a really common argument type. It’s the simplest argument structure there is: Premise, therefore, conclusion. A therefore B. It is never valid because there is absolutely nothing which links the premise to the conclusion. The premise and conclusion can be intuitively related, and these arguments can sometimes even seem reasonable on the surface. But a formal analysis shows us what a disaster this sort of argument always is. You can’t say “A therefore B” without establishing any relationship between A and B. Our answer will almost certainly be something that establishes some connection between our premise and conclusion.
So our premise is about the amaryllis’s natural habitat and our conclusion is about what we should do for our house plant amaryllis to thrive. We need something which links the plant’s well-being to its conditions in its natural habitat.
Answer Choice (A) No. We could not care less about what other plants do. The argument in the stimulus does not stray from the amaryllis.
Answer Choice (B) Well, first of all, this doesn’t sound true at all. Something that can handle a bit of drought sounds like an ideal house plant to me. But that doesn’t matter. It doesn’t have to be true. We don’t know if these plants are hard or easy to care for and we don’t care. Whether they’re harder or easier to keep than other plants has no bearing on our job in helping them thrive.
Answer Choice (C) No, though I can see why this might be attractive. If we’re trying to mimic its natural habitat, wouldn’t this be best? Well, yes. But are we trying to mimic its natural habitat? Not necessarily. We are trying to create conditions in which it will thrive. This answer requires the further assumption that its natural habitat is optimal for it to thrive. We do not know this. Life may find a way, but that doesn’t mean it’s thriving.
Answer Choice (D) Tricky. If it doesn’t thrive then it probably wasn’t dormant long enough. No, this doesn’t need to be true. There could be many other conditions required for this thing to do well, any one of which may explain why a plant might be struggling. Maybe it got too little or too much sun. We just don’t know. This does create some relationship between the premise and the conclusion, though, so it might be tempting.
Correct Answer Choice (E) This looks good, though the test writers do make some effort to disguise it since they never explicitly talk about thriving. But it’s there. It establishes that the plant’s dormancy benefits it beyond merely preventing it from dying. If its dormancy period only prevents death and there is no further benefit, then there is no reason to intentionally subject it to drought conditions. There’s a lot of room between not-dying and thriving. This answer provides us with something more than simply not dying. There is some benefit to dormancy other than just not dying. Now, we may help it thrive by withholding water because we are providing whatever this benefit might be. If this is not true, however, then drought provides no benefit whatsoever and, thus, cannot help us to thrive.
Here we have a flaw question, which we know from the question stem: “The argument is most vulnerable to the criticism at that…” Right away we know our correct answer has to do two things: be descriptively accurate, and describe the flaw of the stimulus. We also know what the wrong answers will do - describe reasoning flaws we’ve seen before, but don’t like up with our stimulus. Once we have a clear understanding of the questrion’s objective, we can proceed into structural analysis of the stimulus.
The argument begins by paying out two factual events; at the same time humans spread to America, several species went extinct. The stimulus goes on to conclude from this information we know that hunting on the part of the humans is what ultimately caused the extinction of these different species.
The word “cause” points out exactly what type of flaw we are dealing with. Our author assumes a causal relationship from a correlation between two variables. Remember that our conclusion, if valid, would be something that must be true on the basis of the premises. But it does not make sense to conclude one thing caused another if all we know is that those two events happened at the same time. Just because they occur at the same time does not preclude the possibility of a 3rd outside factor causing both human migration and the extinctions.
Knowing this stimulus incorrectly assumes causation from correlation, we can jump into the answer choices.
Answer Choice (A) This answer choice is not descriptively accurate. We are not introduced to a viewpoint where humans are seen as “not included in nature”. Rather, we are told that humans are so involved in nature there is an impact on the animals inhabiting this area.
Answer Choice (B) There are a few things that are not descriptively accurate about this answer choice. First, the answer accuses our argument of identifying a “myth” – a belief not based in objective fact and reason. But our issue with the argument is not the lack of reasoning. Our issue is that the reasoning provided does not lead us to our conclusion. Additionally, by telling us that the stimulus “presupposes what it attempts to prove,” answer choice B claims the existence of circular reasoning in our argument. When reasoning is circular, the conclusion is used as the evidence for the conclusion. We do not see an argument in the form of “B is true because B is true.” Knowing this, we can eliminate the answer choice.
Answer Choice (C) This answer choice does not contradict the content of our stimulus, but it is not the flaw of our overall stimulus. It is true that there may have been a different level of significance of the extinctions of animals in modern times versus prehistoric times, our stimulus is not concerned with the past versus the future. Instead, our answer choice has to describe something affecting something else simply because they exist at the same time.
Answer Choice (D) We can’t eliminate this answer choice based on its descriptive accuracy. There very well could have been many other species that went extinct after humans inhabited North America. But whether or not other animals happened to go extinct during this time period does not point out the problem with our stimulus. Our argument takes a specific position on what the extinction of some animals means. Whether or not there were additional extinctions does not point out the causal issue at play in this argument.
Correct Answer Choice (E) This is exactly what we are looking for! This descriptively accurate answer choice points out the issue in our author’s interpretation of the evidence. This is the only answer choice that attacks that interpretation while pointing out the far too strong causal relationship the author concludes.
Here we have a flaw question, which we know from the question stem: “The reasoning that Oscar uses in supporting his prediction is vulnerable to criticism on the grounds that it…” Right away we know our correct answer has to do two things: be descriptively accurate, and describe the flaw of the stimulus. We also know what the wrong answers will do - describe reasoning flaws we’ve seen before, but don’t like up with our stimulus. Once we have a clear understanding of the questrion’s objective, we can proceed into structural analysis of the stimulus.
This question presents us with two speakers. Right away, we should recognize that there are two conclusions and two reasons behind them. Our first speaker begins by telling us that due to emerging technology, speed of information processing will become the single most important factor in determining wealth. By this, Oscar means that countries will no longer be generally rich in the northern hemisphere and generally poor in the southern hemisphere. The first speaker uses this evidence to assert their overall conclusion that a country’s economic state will soon reflect the speed at which they process information.
The assumption in Oscar’s argument is tricky to find. At first glance, the argument does not seem terribly egregious. It makes sense that if tech speed = wealth, then the fastest countries would be the wealthiest and the slowest countries would be the least wealthy. But remember when looking at a flaw question that our conclusion must be forced to occur on the basis of our premises. Oscar is drawing a pretty strong conclusion here. By saying that a country’s wealth will be determined by speed of information processing, the speaker is also assuming that there is not some other factor that is going to be more important in the future. That feels almost like an obvious piece of information. Clearly, if Oscar thinks information processing speed is #1, he does not think some other factor is #1. But this is exactly how the assumption plays out into our correct flaw answer choice.
You may have noticed our question stem does not actually require us to analyze Sylvia’s argument. But, Sylvia does provide good insight into at least one way to describe what is wrong with Oscar’s position. Sylvia tells us that poor countries lack the means to acquire this technology to begin with. As a result, the technology will only worsen the existing wealth disparity between north and south. This is where we can see some disagreement between Oscar and Sylvia. While Oscar believes speed of information processing is going to be the ultimate determining factor, Sylvia identifies the beginning wealth of the country to begin with will actually impact eventual economic performance. The second speaker’s argument can help us confirm what we suspect to be the problem with the argument. Oscar concludes one factor will reign supreme. Sylvia confirms the assumption of our first speaker by saying there is a possibility some other factor will actually play the most important role.
Knowing our correct answer will point out Oscar’s assumption of wealth distribution through the globe, we can proceed into answer elimination.
Answer Choice (A) This answer choice is descriptively accurate, but it is not the issue in Oscar’s argument. The first speaker tells us because speed is the most important factor, the conclusion follows. Whether or not there is another teeny tiny nearly insignificant factor that weighs .05% on wealth generation in a country is not the issue asserted by Oscar’s reasoning.
Answer Choice (B) This answer choice is again descriptively accurate but not what we are looking for as the flaw of Oscar’s position. The failure to establish this wealth division as the most important problem does not address Oscar’s assumption about the dissolution of that northern and southern hemisphere divide.
Correct Answer Choice (C) This answer choice is exactly what we are looking for. This descriptively correct answer choice is the only one that points out the same possibility as Sylvia; maybe processing speed is not the guaranteed determinant of wealth. Instead, other factors such as beginning economic performance would change predicted wealth levels. This is the only answer choice that hits on the reasoning of Oscar’s argument. Although Sylvia isn’t the one telling us about a “combination” of other factors, this answer choice does point out the importance of some other considerations.
Answer Choice (D) This answer choice is descriptively accurate, but not the ultimate issue of our argument. While it is true that Oscar does not provide us with an exact reason as to why technology will provide only beneficial effects, that is not the concern of our discussion. Rather than debating whether this technology will be purely beneficial, Oscar explores the consequences of one aspect.
Answer Choice (E) This answer choice is again descriptively accurate but not the ultimate issue in our discussion. Whether or not there is a distinction between the rich people in wealthy countries versus slightly less rich people in wealthy countries does not hone in on Oscar’s assumption about the factors impacting wealth and the adaptation of technology.
The argument begins with an explanation of the pharmacists' position; doctors should not sell medicine to patients due to the risk of over prescribing them. All seems well until we get to our speaker’s position. Rather than responding to the overprescription issue, the patient attacks the speaker and their motives for having that opinion. On the basis of those motives, our patient concludes that we can’t trust what the pharmacists are saying.
The answer to a method of reasoning question is going to exist in the evidence or explanation of our conclusion. One word we can use to summarize this stimulus would be “interests.” Using this prediction can help us effectively narrow down the answer choices.
Answer Choice (A) This answer choice is incorrect because we are not actually refuting any of the pharmacists’ claims - we just cannot trust the opinion of that group entirely.
Correct Answer Choice (B) This answer choice lines up well with our prediction, confirming our speaker is attacking their opponent rather than the basis of their argument. This is our correct answer!
Answer Choice (C) Similar to answer choice A, we can eliminate this one based on the scope. Rather than refuting the argument they are faced with, our patient pursues a personal attack.
Answer Choice (D) We don’t have any information on what the general public thinks about all this. So, we can eliminate this answer choice.
Answer Choice (E) While our prediction regards a personal attack, this answer choice attacks the qualification of the pharmacist group. This is not what we are looking for.
This is a main conclusion question, which we can tell from the question stem, “The main point in Kim’s argument is that...”
Kim opens their argument with a statement about a claim from other people, stating that electric cars running on batteries might pose a solution to air pollution. Then, Kim adds in their take on that claim: apparently “some people” conveniently forgot about how batteries recharge, via electricity. Most of which comes from burning fossil fuels, which also pollutes the air. Kim says that because the electricity-generating facilities we have right now are at capacity, if we want more electric cars on the road, we would have to build more of those facilities. Alright, now were getting to Kim’s point, led in with “so” (a common conclusion indicator) to the extreme of the electric car proposal: even if we replaced literally all of the gas cars with electric ones, we’d just be trading of one form of air pollution for another. Looks like that’s our conclusion! In other words, Kim is saying battery-powered electric cars won’t actually solve the pollution issue as they’ll just contribute to it by different means.
Answer choice (A) says that Kim’s main conclusion is that to build more electric cars we need to build more electricity generating facilities. That was stated in the argument, but it was just one piece of support that made Kim’s final conclusion more likely to be true. It can’t be our answer, then, because it’s just a premise.
Answer choice (B) comes totally out of left field. Did Kim ever go as far as saying it’s absolutely necessary for people to just drive less to reduce air pollution? Goodness no, they’re just saying electric cars aren’t a great solution.
Answer choice (C) is not stated in the argument either. Can we point to any place in the stimulus where Kim claims that all types of cars are equally bad for air pollution? Nope.
Correct Answer choice (D) looks like a perfect rephrase of our prediction. Although it may not be stated word-for-word in the argument, there’s no way it’s not Kim’s main point. Why would Kim have said everything they did, ending on the note that electric cars are just an exchange of one form of pollution for another, if they didn’t think that battery-powered cars were not a viable solution as (D) states? This is our winner!
Answer choice (E) also goes too far and was never stated or supported in the argument. We don’t know if Kim thinks gas-powered cars are here to stay, we just know they don’t think electric cars are a viable solution.
Here we have a flaw question, which we know from the question stem: “The reasoning in the argument is most vulnerable to criticism on which one of the following grounds?” Right away we know our correct answer has to do two things: be descriptively accurate, and describe the flaw of the stimulus. We also know what the wrong answers will do - describe reasoning flaws we’ve seen before, but don’t like up with our stimulus. Once we have a clear understanding of the questrion’s objective, we can proceed into structural analysis of the stimulus.
The stimulus begins with an if-then statement: if Blankenship switches suppliers, they will not turn a profit. Based on this sentence our speaker concludes that if Blankenship does in fact show no profit, it must have been because they switched suppliers.
Diagramming the relationships can help us see the conditional reasoning mistake being made. While we know that a switch in suppliers guarantees a lack of profit, we cannot simply switch around our sufficient and necessary conditions in the conclusion. The evidence presented by the author tells us that S (switch) → /P (no profit).
From here we can conclude only a few things. We could correctly conclude the contrapositive to be the case, that if we do in fact turn a profit we know the company has not switched suppliers during their production run (P → /S). We also know that if the switch occurs profit will be affected. However, we are not able to draw the conclusion that because we have the necessary condition of no profit does not mean we can confirm the existence of our sufficient condition - switching suppliers.
Knowing our speaker mistakes the information we can conclude from a conditional relationship, we can proceed into the answer choices.
Answer Choice (A) Answer choice A is not descriptively accurate. By accusing our speaker of circular reasoning, this answer claims the argument uses its conclusion as evidence for the argument. Without a statement telling us “the conclusion is correct because the conclusion is correct,” we can eliminate this answer choice from consideration.
Correct Answer Choice (B) This is exactly what we are looking for. This descriptively accurate answer choice correctly points out the mistaken conditional reasoning made in the stimulus. Simply because we know S → /P, this does not mean we can just switch the arrow in the opposite direction like our speaker does in the conclusion.
Answer Choice (C) This answer choice is also not descriptively accurate. Rather than shifting the meaning of a word over the course of the argument, our speaker confuses the direction of the relationships between terms that remain consistent in meaning.
Answer Choice (D) Answer choice D is not descriptively accurate. We have no information to determine whether or not Blankenship represents an exception case or a run-of-the-mill operation. Even still, Blankenship being a unique case would not change the conditional flaw presented in the author’s reasoning.
Answer Choice (E) This is not what we are looking for. Accusing the speaker of failing to consider some third possible event does not identify the mistaken reversal occurring in the stimulus. This answer choice aligns with the common correlation/causation flaw often presented in flaw questions - but that is not the issue here.