This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diuretics and Antidiuretics, Subject name: Pharmacology
[{'content': 'Drug causing gynecomastia is: \nSelect and explain. \nA. Spironolactone, B. Rifampicin, C. Penicillin, D. Bumetanide', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (A) Spironolactone(Ref: KDT 8/e p635)Important drugs causing gynaecomastia are:D - DigitalisI - IsoniazidS - SpironolactoneC - Cimetidine (and Ketoconazole)O - Oestrogens (and anti-testosterones)', 'role': 'assistant'}]