This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anxiety disorders stress disorders and grief, Subject name: Psychiatry
[{'content': 'Male with symptoms mimicking hea disease with normal ECG and X-ray, the diagnosis is \nSelect and explain. \nA. Angina Pectoris, B. Panic attack, C. ANS instability, D. Vasovagal attack', 'role': 'user'}, {'content': 'Answer: B \nExplanation: A panic disorder is characterised by discrete episodes of acute anxiety. The onset is usually in the early third decade with often a chronic course.The panic attacks occur recurrently every few days. The episode is usually sudden in onset, lasts for few minutes and is characterised by very severe anxiety. (Ref: a sho textbook of psychiatry, Niraj Ahuja, 7th edition, pg no.90)', 'role': 'assistant'}]