Evidence that people in a posthypnotic state have no difficulty consciously recalling everything they had experienced while under hypnosis would most clearly serve to challenge

A) frequency theory.
B) place theory.
C) dissociation theory.
D) the McGurk effect.

Dissociation theory proposes that hypnosis involves a split in consciousness, where one part responds to suggestions while another part remains aware of reality. If individuals in a posthypnotic state can consciously recall everything they experienced while under hypnosis, it challenges the idea of a split in consciousness and thus challenges dissociation theory. Option A (frequency theory) and B (place theory) are theories related to sound perception and have no relevance to hypnosis. Option D (the McGurk effect) is a phenomenon related to audio-visual perception and has no relevance to posthypnotic state.