Gervase Has Been Diagnosed with Agoraphobia with Panic Attacks

Gervase has been diagnosed with agoraphobia with panic attacks.
a. What type of psychotherapy has been proven to be most effective for treating Gervase's disorder?
b. Explain one therapeutic technique that is effective for treating Gervase's fear of situations that he cannot escape (his agoraphobia).
c. Explain one (different) therapeutic technique that is effective for treating Gervase's overwhelming terror (his panic attacks).