Final answer:
The family therapist in this scenario likely agrees with the Systems therapy approach, which focuses on understanding the dynamics of the entire family system and how changes within the system can impact individual behaviors.
Step-by-step explanation:
The family therapist in this scenario likely agrees with the Systems therapy approach. Systems therapy focuses on understanding the dynamics of the entire family system and how changes within the system can impact individual behaviors. By addressing the family context and dynamics, the therapist believes that Marcia's problem behavior will change as well.