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
[{'content': 'What is the most characteristic symptom in a lady diagnosed with Pheochromocytoma? \nSelect and explain. \nA. Sweating attacks, B. Weight loss, C. Ohostatic hypotension, D. Paroxysmal hypeension', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pheochromocytomas and paragangliomas are catecholamine-producing tumors derived from the sympathetic or parasympathetic nervous system. These tumors may arise sporadically or be inherited as features of multiple endocrine neoplasia type 2. The "rule of tens" for pheochromocytomas states that about 10% are bilateral, 10% are extraadrenal, and 10% are malignant. However, these percentages are higher in the inherited syndromes. The clinical presentation is so variable that Pheochromocytoma has been termed "the great masquerader". The dominant sign is hypeension. Classically, patients have episodic hypeension, but sustained hypeension is also frequent.', 'role': 'assistant'}]