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: Pharmacology
[{'content': 'Aspirin is used in the prophylaxis of myocardial infarction because it results in : \nSelect and explain. \nA. Inhibition of thromboxane synthetase, B. Inhibition of cyclooxygenase, C. Decreased serum lipids, D. Coronary steal phenomenon', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]