You are assessing a military veteran complaining of a headache, visual disturbances, and generalized anxiety. You suspect that he may be suffering from post-traumatic stress disorder (PTSD). What questions would be most appropriate in getting additional information regarding the possibility of PTSD?

A) "Were you forced to kill anyone?"
B) "What branch of the military did you serve?"
C) "Where did you see combat?"
D) "Do you need alcohol to get through the day?"

C