Leads to wrong conclusion. (A) allows us to conclude that it’s reasonable to take a strong position on something if we meet certain conditions. But we’re trying to prove that one should NOT take a strong position on issue. (”If X, then reasonable to take strong position” can NEVER prove that it’s unreasonable to take a strong position.)

(B) doesn’t help us conclude that one should not take a strong position on something. (B) is designed to help us conclude that we shouldn’t misinterpret or ignore evidence. But it doesn’t tell us what’s required in order for it to be appropriate to take a strong position.

Helps build a bridge from the premise to the conclusion. We know from a premise that if you haven’t considered all conflicting evidence, then you don’t understand an issue fully. (C), then, implies that if you haven’t considered all conflicting evidence, then you should not take a strong position on it.

(D) relates to an argument that concludes that one should try to under an issue fully. But the argument in the stimulus concludes that one should not take a strong position on something if you haven’t considered conflicting evidence. (D) doesn’t relate to when one should not take a strong position on an issue.

Wrong trigger. (E) could lead to the conclusion that one shouldn’t take a strong position on an issue if there is NO important evidence conflicting with that position. But the premises didn’t establish that there is no important evidence conflicting with a position. The premises concern what happens if there IS conflicting evidence and you don’t consider that evidence.