Answer: D) Modeling
Explanation:
Modeling is defined as the practice in which representation of something or replica is presented that can be followed or copied by other for learning, understanding etc.
According to the question, Marcia is practicing modeling by imitating the same act or role that is done by therapist for confronting others in different situation so that she can understand concept.
Other options are incorrect because aversion therapy,shaping and systematic desensitization method is not used for making Marcia practice the same manner to confront people in different situation.Thus, the correct option is option(D).