Answer:
The correct answer is D. Systematic desensitization.
Step-by-step explanation:
In psycho-therapy terms, Systematic desensitization is defined as a therapy from the behavioral which main goal is to remove irrational phobias gradually and fears by inducing a relaxating stimuli where the fear condition should appear using a technique called counter conditioning. In Juan's case his phobia is treated with this therapy because of how he's exposed to smaller and smaller places and in each step he's applying the relaxating stimuli to gradually overcome his fearproducing item.