Charles Has Recently Come Back from the War

Charles has recently come back from the war. While in the war, he was severely injured when a bomb blew up the truck he was in (everyone else in the truck was killed) . Since coming home two months ago, he has been having nightmares and flashbacks where he re-experiences the bombing. He is also easily startled and very anxious. He went to see his doctor and was diagnosed as having

A) dissociative identity disorder.
B) a personality disorder.
C) posttraumatic stress disorder.
D) acute stress disorder.