This is a sufficient assumption (SA) question because the question stem says: “conclusion is properly drawn if which one of the following is assumed?”
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it valid. Our rule/prephrase will look like: if [premise], then [conclusion].
Our first sentence looks like a straightforward premise: visits to the hospital by heroin users increased by 25% in the 1980s.
The next sentence provides a hypothesis/conclusion to the phenomenon: the use of heroin rose in the 80s. The argument wants us to believe that if visits to the hospital by heroin users increased, then use increased. Why should I believe that? There could be a ton of other reasons why this would not be true! Maybe the stigma around heroin use decreased, so people were more willing to go in for help but usage is the same. Maybe that year, they started lacing heroin with something that warranted a visit to the hospital but usage didn’t increase. The list goes on!
What we need here is a rule that discounts all of those possibilities, something like “if hospital visits by heroin users are increasing, the use of heroin is increasing.” Now, if we plug this rule back into the stimulus, in a world in which heroin users increasingly go to the hospital, it must also be true that the use of heroin is increasing. We sandwich the premise and conclusion together in a conditional rule, bridging them to help make our argument valid. (Note that we’re not saying one causes the other, we’re just establishing a relationship between the two).
Answer Choice (A) This answer choice doesn’t address our argument. We’re trying to show that with increasing hospital visits, the use of heroin increases. What does seeking medical care at specific stages of heroin use have to do with increased hospital visits during a fixed period of time? This answer choice doesn’t fit into the argument at all.
Answer Choice (B) This interacts with our argument by pointing out that some of the visits have been made by the same person. This could mean that the number of users and the amount of use is the same, just that some people come in more frequently, which weakens our argument.
Correct Answer Choice (C) This establishes the positive correlation between hospital visits by heroin users and the overall use of heroin.
Answer Choice (D) If new methods are less hazardous, this could explain why use has increased. However, if use is safer, why are hospital visits increasing in the first place? Remember, we need to validate our entire argument, not just the conclusion. This is out.
Answer Choice (E) This could interact with the premise portion of our argument if we assume that they increasingly began identifying themselves as heroin users when they come to the hospital in the 80s, but that’s a big stretch since we don’t know if this has always been the case or if it became a norm in the 80s. Even if we can assume this, it still doesn’t help validate our conclusion. In fact, it could weaken it: it’s not that use has increased, it’s that more people are open about their use of heroin.
Here we have a Method of Reasoning question, which we know from the question stem: “The argumentative strategy of the investigator quoted is to…”
After correctly identifying the question type we can use structural analysis to describe the Method of Reasoning used by our speaker.
The stimulus begins by providing us with a phenomenon. Disturbances in the desert are found that appear on footpaths that expand for long distances. The question requires us to describe the reasoning used by the quoted investigator. The investigator concludes the discovered paths could not have been incan roads because the roads would be of little use to the incas due to their adjacent placement and abrupt ending point.
Knowing that our correct answer will highlight how the investigator questions the value the roads would have served the Incas, we can proceed into answer choice elimination.
Answer Choice (A) This answer choice is not descriptively accurate because it brings up the idea of counterevidence. Our investigator does not depend on additional evidence to make their claim. Instead the investigator reinterprets the evidence we already have. For this reason we can eliminate answer choice A.
Answer Choice (B) Similarly to answer choice A, this is not descriptively accurate based on the answer choice’s summary of evidence. This answer choice suggests that the investigator provides new information to support their conclusion. Knowing our investigator questions the evidence we already have, we can eliminate this answer choice.
Correct Answer Choice (C) This is exactly what we are looking for. This is the only answer choice that points out the investigator’s questioning of current evidence. This answer choice correctly highlights how the investigator’s conclusion only goes so far as to say what the function of the pathways likely did not serve.
Answer Choice (D) In order for this answer choice to be correct our stimulus would have to refer to the methods used by various investigators to determine their conclusions. Without any reference to the methods used to compile this information we can eliminate answer choice D.
Answer Choice (E) This answer choice is not correct because it claims that our stimulus reconciles two different perspectives. If this were correct we would expect our stimulus to discuss the joining or explanation of a conflict between two different theories. Without this information we can eliminate answer choice E.
Here we have a Method of Reasoning question, which we know from the question stem: “The basic step in Eileen’s method of attacking James’ argument is to…”
After correctly identifying the question type we can use structural analysis to describe the Method of Reasoning used by our speaker, Eileen.
Immediately we should note we have two speakers in our stimulus. That means we need to be on the lookout for two conclusions and two sets of explanations. James begins the conversation by telling us that at their house they have complete personal freedom. On the basis of that freedom, James concludes the government is ignoring the right of individuals to set smoking policies on their own property. This argument is not a good one. Sure, James can do whatever they want in their own home. But boarding a domestic flight does not mean one should receive the same rights as if they were in the privacy of their own home. James has improperly assumed there is no difference between the rights someone has at home versus the rights someone has on an airplane around the general public.
Eileen points out this consideration exactly. In their response, our second speaker highlights what James has assumed. While James has assumed the government has violated a right by not allowing people to do as they please, Eileen points out the difference between actions at home versus on a domestic flight. Smoking on a domestic flight impacts others far more than it would if James were to smoke in his own home.
Knowing that Eileen exactly hits on the assumption of James’ argument, we can proceed into answer choice elimination.
Correct Answer Choice (A) This is exactly what we are looking for! This is the only answer choice that correctly points out how Eileen highlights the apparent differences between an individual at home versus an individual on an airplane. By drawing a distinction between these two locations, Eileen effectively points out the weakness of James’s argument.
Answer Choice (B) This answer choice is not correct. Without the existence of a term being explained in the stimulus we cannot select an answer that suggests Eileen is providing some sort of definition.
Answer Choice (C) This answer choice is not correct. If our correct answer were going to include an analogy, we would be able to identify two items being compared through analogy in Eileen’s part of the discussion.
Answer Choice (D) This answer choice is not correct because of the term contradiction. Contradicting something means our argument provides directly contrary pieces of information. But Eileen does not contradict or say James is wrong – instead, Eileen explains how the base assumption James needs in the first place does not exist.
Answer Choice (E) If this were our correct answer choice, we would see some sort of reference to the motivation of James or others in smoking on airplanes versus in their own homes. Without this information we cannot select answer choice E.