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 are risk factors for atherosclerosis except: \nSelect and explain. \nA. Increased waist-hip ratio, B. Hyperhomocysteinemia, C. Decreased fibrinogen levels, D. Decreased HDL levels', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]