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': 'An old man has enlarged prostate. Which of the following may be use to suppress his prostatic growth: \nSelect and explain. \nA. Spironolactone, B. Ketoconazole, C. Finasteride, D. Flutamide', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]