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': 'The level of LDL cholesterol at which therapy should be initiated in a patient without a coronary artery disease and no risk factors is - \nSelect and explain. \nA. 100 mg./dl, B. 130 mg./dl, C. 160 mg./dl, D. 190 mg./dl', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]