A positive correlation has been found

Answer choices

1. A

   Strengthens9% picked this

   In cities where there are high concentrations of many air pollutants but little if any soot in the air, the frequency of the ailment

   This answer suggests that soot is not the cause of Ailment X, so it strengthens this author's conclusion. If the ailment is still just as prevalent even in cities where there's not much soot in the air, then soot doesn't seem to be the cause.

   9%
2. B

   Untriggered Conditional21% picked this

   If the ailment rarely occurs except in cities in which there are large amounts of soot in the air, then the soot is

   The outcome of this conditional would be the perfect counterpunch to this author's conclusion, but we only get that outcome if we establish that the trigger is true. Do we know that the ailment rarely occurs except in cities in which there's lots of soot in the air? No, we've never been told that. Thus, this hypothetical idea has no impact.

   21%
3. C

   Correct60% picked this

   In each of the cities where there are large amounts of soot in the air but little other air pollution, the frequency of the

   Why this is right

   This both strongly suggests that soot is the causal difference-maker and that the other pollutants are not. There are cities where there is high soot, but not the "other pollutants" that the author is thinking cause ailment X, and yet the incidence of ailment X is just as high as anywhere else. So that suggests that soot is what's causing the incidence of ailment X. If you believe that soot causes X, then we would say this data point strengthens by providing a "Yes Cause, Yes Effect" example. If you believe (as the author does) that these other pollutants cause X, then we would say this data point weakens by providing a "Effect without Cause" data point, since the effect is present (high incidence of X) even though the cause is absent (the other pollutants aren't there).

   Skill tested: Weaken · how this choice captures the argument's function is the move to repeat next time.

   60%
4. D

   Strengthens, if anything6% picked this

   If high concentrations of many different pollutants in a city's air are correlated with a high frequency of the ailment among that city's population,

   This is also a conditional, so it doesn't have any value unless we can establish the trigger. If we do trigger the conditional, the outcome would actually help the author to argue that it's these other air pollutants that are causing the incidence of ailment X. The argument mostly establishes the trigger. Higher rates of ailment X are correlated with high levels of soot, and high levels of soot are correlated with high levels of these other pollutants. If A is correlated with B, and B is correlated with C, that doesn't necessarily mean that A is correlated with C, but it suggests it probably is. Luckily we don't need to dig deep on whether the trigger is established because the outcome wouldn't be helpful in terms of weakening the argument.

   6%
5. E

   Somewhat Strengthens & Weakens4% picked this

   In cities in which there are high concentrations of many air pollutants, there are generally also high concentrations of other forms of pollution that

   This is an interesting answer, because it suggests that ailment X may actually be caused by some other form of pollution (not airborne). That somewhat goes against the idea the author is suggesting, which is that "other air pollutants" are causing ailment X, but it strengthens the author's conclusion that "the soot itself is probably not causing ailment X". If an answer is a mixed bag, it will almost always lose out to an answer that purely strengthens or weakens. The fact that this answer is saying "other forms of pollution very likely contribute causally to the ailment" also means that it's not actively denying the author's idea that air pollutants cause X. It can just be adding to that idea, saying "Yes and these other forms of pollution also contribute to X".

   4%