What Is One Factor That Distinguishes Between Traditional Exposure-Based Treatments

What is one factor that distinguishes between traditional exposure-based treatments for panic disorder and the more recent panic control treatment (PCT) developed at one of Barlow's clinics?

A) Exposure to the interoceptive sensations associated with panic attacks
B) Referral to a psychiatrist for medication monitoring
C) Traditional exposure-based treatments resulting in a higher rate of cures
D) As part of PCT, the therapist accompanying the patient on "reality testing" activities