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': 'True statement about obesity - \nSelect and explain. \nA. Dexenfluramine is drug of choice, B. Sibutramine is only or epinephrine uptake inhibitor, C. According to WHO body mass index greater then 25 is overweight, D. Long term effect of orlistat is known', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]