Why Do Many People with Panic Disorder Continue to Believe

Why do many people with panic disorder continue to believe they are having a heart attack despite the fact that they never have?

A) They continue to go through classical conditioned learning experiences each time they have a panic attack.
B) They tend to engage in "safety behaviors" that they believe are the reason the catastrophe didn't happen.
C) They tell themselves that physicians may have missed earlier heart attacks.
D) They have such a high level of fear that learning is not possible.