I chose answer choice A despite the fact that deep down, I knew that it probably wasn't right because I would have to assume fish only come from oceans and seas (when really, fish can come from lakes, ponds, rivers, etc!).

B was tricky because I became too reliant on the pattern of "some" answer choices. Typically, when we saw the word "some," we'd dismiss it because we would have to assume that the subject in the stimulus fell into the category. Some doesn't mean all so we'd have to make the assumption in order for the answer choice to apply.

HOWEVER, I now understand why B was correct - WEAKENING questions are like this: "Despite the premise and conclusion being true, it still may be the case that..." There could be another fact out there in the world that casts doubt or brings skepticism to the author's argument.

Weakening questions are not about proving what's right or wrong but rather, it's about questioning the logic behind the argument

That's why B was correct. Even if it IS true that PIE has not word for sea but has words for "wolf" "winter" and "snow," that doesn't NECESSARILY mean that a lack of certain words indicates their living conditions (or where they don't live). It could literally be the case that they just didn't make a word up for sea for whatever reason despite the fact that they live by the sea.

Hello! Interested as well.

JY's wording for explaining answer choice D is a bit confusing, so I'll leave my reasoning down below if it's any help to anyone.

Correct Answer D: The argument rejects the possibility that what has not been proven is nevertheless true.

Just because something hasn't been proven to be true doesn't mean it is false/untrue. No proof of truth does not mean it must be false. There is still the possibility that it could be true, which is what answer choice D is claiming.

Premise: "No one has been able to show that these do not harm tire tread."

Conclusion: Therefore, "we can assume that underinflation or overinflation of tires harms their tread."

While there is no proof currently that underinflation or overinflation of tires do not harm tread, this doesn't mean we can conclude the opposite and say they, indeed, DO harm tread.

No proof of hurting tread is not an indicator of fact.

It could well be that no one cared enough to show proof that the underinflation or overinflation of tires don't harm tread because they thought it was basic knowledge that underinflation or overinflation doesn't negatively affect tread of tires. So, while there's no "evidence" of no harm, it could still be true that they in fact do not harm tread.

Hello! I'm interested.