Final answer:
The therapist was attempting to make use of posthypnotic suggestion.
Step-by-step explanation:
The therapist was attempting to make use of posthypnotic suggestion. Posthypnotic suggestion is a technique used in hypnosis where the therapist gives a suggestion during the hypnotic state that will be carried out after the person is brought out of hypnosis. In this case, the therapist told Chinua that he would feel nauseous whenever he reached for a cigarette.