Passage Summary: The author thinks that because some good speakers are impressive, and rude speakers aren't 'good,' then rude speakers can't possibly be impressive.

Conclusion: No speakers who use obscenity impress their audiences.

Reasoning: Some eloquent speakers are impressive, but since obscene speakers are not eloquent, they cannot be impressive.

Analysis: The flaw here is a classic formal logic error: just because a subset of 'eloquent' people are 'impressive' doesn't mean 'impressive' is exclusive to them. In abstract terms, the argument says: Some A are B; C is not A; therefore, no C is B. This ignores the possibility that someone could be impressive (B) without being eloquent (A). We need to find an answer choice that follows this exact pattern of denying the possibility of a trait just because the subject lacks a specific sufficient condition mentioned earlier.