Although powerfully persuasive, comparisons are risky. Their soundness, logical strength, and relevance can easily be _______________.

A) demonstrated
B) questioned
C) confirmed
D) validated
E) ignored

The sentence suggests that comparisons can be risky because their soundness, logical strength, and relevance can be questioned. This implies that comparisons are not always airtight and can be subject to criticism or doubt. Therefore, the best choice is B, questioned. The other options (demonstrated, confirmed, validated, and ignored) do not capture the uncertain nature of comparisons and how they can be challenged.