Derek suddenly felt his hands and legs go numb and started shaking involuntarily while preparing for his high school final semester. The acuteness of the problem forced his parents to consult a clinician. When asked, the clinician was told that it was the first time Derek had suffered from any of these symptoms. Derek is most likely experiencing _____
(A) a panic attack.
(B) specific phobia.
(C) generalized anxiety disorder.
(D) obsessive-compulsive disorder.

Panic attacks are temporary periods of scary, fear, anxiety, and other negative feelings, that occur spontaneously when people are in situations that can be considered maddening or overwhelming. Additionally, a panic attack produces physical symptoms like tachycardia, shortness of breath, pulmonary hyperventilation, involuntarily shaking, tremor or dizziness. From above, it can be said that Derek had a panic attack because he was in a situation that caused overwhelming for him and his symptoms were spontaneous and involuntary. So, the correct answer is A. A panic attack.