Many Soldiers Returning from the War in Iraq Have Suffered

Multiple Choice

Many soldiers returning from the war in Iraq have suffered from post-traumatic stress disorder (PTSD) . However, your friend from high school who has returned from a protracted active deployment seems to be coping well even though he had some truly horrible experiences. How might you explain this with regard to the biological and environmental contributions to behaviour?

A) He may not have a genetic susceptibility to PTSD.
B) Environment isn't an important factor in determining behaviour.
C) He inherited a genetic predisposition to PTSD.
D) The experiences really are not as bad as people say.