Nina visits a therapist in an attempt to treat her social ph…

Nina visits a therapist in an attempt to treat her social phobia. During the first several sessions she spends time learning various relaxation techniques. Then her therapist has her create a hierarchy of situations that cause her anxiety from the least anxiety-producing to the most fearful. Slowly, the therapist guides her in encountering each situation on the hierarchy while incorporating the relaxation techniques to ensure that Nina remains relaxed in each situation. Which technique is the therapist using to change Nina’s reactions?