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': 'Treatment of choice for pneumocystis carinii pneumonia is: \nSelect and explain. \nA. Trimethoprim/sulfamethoxazole, B. Erythromycin, C. Ofloxacin, D. Tetracycline', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]