Terry complains that he is experiencing recurrent episodes of lightheadedness, rapid breathing, and dizziness, especially as he attempts to leave his house. The symptoms have become so severe that, in fact, he is leaving his house less and less frequently. He now only goes to the grocery store in the company of his sister. Once in the store, he checks immediately for the exits and windows.A.Posttraumatic stress disorderB.Panic disorderC.AgoraphobiaD.Obsessive-compulsive disorder