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': 'All of the following may be raised in carcinoid syndrome, Except \nSelect and explain. \nA. 5HIAA, B. 5HT, C. 5HTP, D. VMA', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer is D (VMA): 5HIAA, 5HT, 5HTP are metabolites of Trvptophan / Serotonin that may be elevated in carcinoid tumors. Vanillvl mandilic acid (VMA) is the principal metabolite of catecholamines secreted by adrenal medulla. Elevated VMA levels in urine is a feature of increased catecholamine secreting tumors, typically pheochromocytomas (and not carcinoid tumors).', 'role': 'assistant'}]