Nasir occasionally experiences periods of intense overwhelming dread that come about for no reason. These periods are marked by trembling, heart palpitations, and chills, and the feeling that he is losing control.
Nasir might be diagnosed as having:

A. post-traumatic stress.
B. generalized anxiety.
C. phobic disorder.
D. panic disorder.

B)

Explanation:

Nasir's behavior can be diagnosed as generalized anxiety because of the feelings that he is having and those are chills, palpitations, feeling of losing control and more.

If he had post-traumatic stress, panic or phobic disorder those feelings would be represented in a situation that is triggering him and reminding him of some past event but the anxiety is showing sometimes for no reason when the body became used to them.

answer: there were new carvings etched into the back of the sculpture and each shoulder was turned into a symbol of the birdman.