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': 'Oligospermia is a side effect of which of the following drug: \nSelect and explain. \nA. Methotrexate, B. D-Penicillamine, C. Lefluonamide, D. Hydroxychloroquine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Methotrexate', 'role': 'assistant'}]