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
Increased risk of Myocardial infarction is associated with which amino acid 
Select and explain. 
A. Methionine, B. Homocystine, C. Ornithine, D. Melatonin
B: Homocystine
Answer: B: Homocystine 
Explanation: High blood level of homocystine is a risk factor for atherosclerosis and MI.