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': 'Which of the following drug is corticosteroid synthesis inhibitor? \nSelect and explain. \nA. Metyrapone, B. Finasteride, C. Flutamide, D. Mifepristone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Metyrapone inhibits 11 -\xa0β - hydroxylase enzyme and prevents synthesis of corticosteroids.', 'role': 'assistant'}]