What Key Factor Makes the Difference Between People Who Develop

What key factor makes the difference between people who develop panic disorder and those who suffer traumatic events and have a few panic attacks but do not develop the disorder?

A) how the person interprets his or her bodily reaction to the trauma
B) whether the traumatic event involves personal injury to oneself or a close friend
C) if the traumatic event occurs within three months of the individual's birthday or another major holiday
D) if the traumatic event does not involve a bomb or other explosive device.