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': 'The 5α reductase inhibitor that has been found to be effective both in benign prostatic hypertrophy and male pattern baldness is: \nSelect and explain. \nA. Flutamide, B. Finasteride, C. Prazosin, D. Minoxidil', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]