Q7 - Although some animals exhibit

[mshinners]

Question Type:
Strengthen

Stimulus Breakdown:
Humans are the only animals that get bad poison ivy rashes. Some animals even live in it. Therefore, poison ivy probably didn't evolve poison as a defense mechanism.

Answer Anticipation:
Since this conclusion rules out one possibility, there are any number of things that could serve as strengtheners. Anything that shows poison ivy not hurting things would strengthen this conclusion. Also, any answer that provides an alternative reason for urushiol's development would help this argument. We should be on the lookout for both.

Correct answer:
(B)

Answer choice analysis:
(A) Neutral. Without knowing if dead/brittle branches also have urushiol, this answer doesn't necessarily impact the conclusion.

(B) Bingo. This answer choice is similar to the premise about rats, showing that urushiol doesn't serve as a defense. More evidence for the conclusion!

(C) If anything, opposite. While this answer isn't specific enough to definitively weaken the conclusion, it cuts against it by stating defense is a common reason to develop a chemical.

(D) If anything, opposite. This answer is pretty neutral to the argument since we already know humans are allergic to urushiol. However, if anything, it cuts against the argument by showing just how poisonous this substance is to humans!

(E) If anything, opposite. To see this as a weakener, we'd have to make some jumps, which automatically rules it out. However, if anything, it points in that direction by showing that poison ivy/oak seem to be concentrated in human areas, suggesting that any defenses they've developed could have been in response to pressure from humans.

Takeaway/Pattern:
For Strengthen questions, if an answer seems to cut agains the argument - even if it's actually neutral - you should cut it and move on without considering it too closely.

#officialexplanation

[AshH953]

I guess I really went too far to think that there is a leap from the premise 'humans are hurt' to conclusion 'non-defending at all' and we need to fill it the gap by suggesting they do not develop against humans. That's why I was tricked into E.