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: Biochemistry
[{'content': 'Increased risk of Myocardial infarction is associated with which amino acid \nSelect and explain. \nA. Methionine, B. Homocystine, C. Ornithine, D. Melatonin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: High blood level of homocystine is a risk factor for atherosclerosis and MI.', 'role': 'assistant'}]