Answer: B
Explanation: The correct option is letter B, cognitive-behavioral therapy plus and antidepressant. When treating anxiety disorders you discover in almost every case that is an emotional disorder underneath, because anguish is the other side of anxiety.
If you treat an anxiety disorders such as social anxiety disorder only with the CBT (cognitive-behavioral therapy) you will be leaving aside the anguish and therefore it will probably won't have effect as a long term plan.
With a antidepressant solely based treatment, you will be leaving aside the cognitive part and therefore it won't have a long term effect neither.