Martha and Stan are newlyweds. They see a therapist because Stan is afraid of sexual intercourse. The therapist asks Stan exactly which acts make him anxious, constructs a hierarchy of those threatening acts, teaches him to relax,

and asks him to imagine each threatening scene in the hierarchy and use the relaxation technique to reduce his anxiety. The therapist is using ________.

a. negative reinforcement
b. systematic desensitization
c. stepwise regression
d. aversive conditioning

Answer: b