This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Most common paroxysmal symptom of pheochromocytoma: 
Select and explain. 
A. Headache, B. Palpitation, C. Abdominal pain, D. Hypotension
A: Headache
Answer: A: Headache 
Explanation: Answer is A (Headache): The single most common paroxysmal symptom repoed in patients with pheochromocytoma is headache 'Most adult patients have paroxysmal symptoms, lasting minutes to hours, consisting of headache (80%), perspiration (70%), and palpitations (60%)' - Endocrine Tumors (PMPH-USA, 2003)/ 104 The three most commonly repoed paroxysmal symptoms in pheochromocytoma are Headache, Palpitations and Excessive or inappropriate sweating. Almost all patients will have one of three symptoms above and most will have at least two. The most common and predominant sign of Pheochromocytoma is Hypeension