Why D? Why not C?

Hello @samlhoover, I was able to eliminate C because I was unable to find any part of the passage that discusses intentional deception by a witness. The disadvantages of hypnosis are described in the third paragraph. 1. Hypnosis can result in "false confidence" 2. Not all people are susceptible to hypnosis. The false confidence problem provides support for answer choice D. If a hypnotized witness claimed to be highly certain of a particular fact, the interviewer would have reason to be skeptical of that witness's certainty.

Why would the interviewer be skeptical?