Darcy is sitting at her desk in her office one day when, without warning, her heart begins racing rapidly, she has a sensation of being "out of her body," and she experiences dulled vision and hearing, rapid breathing, and sweating. she thinks she is having a heart attack. nothing she is doing seems to have caused such an episode. her symptoms most resemble

a. a phobic disorder
b. a panic attack
c. post-traumatic stress
d. an affective disorder