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': 'Cholesterol level for prevention of coronary artery disease - \nSelect and explain. \nA. <250 mg/dl, B. < 220 mg/d1, C. <300 mg/dl, D. 200 mg/dl', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]