This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'Which of the following drug is a potassium channel opener \nSelect and explain. \nA. Nifedipine, B. Minoxidil, C. Enalapril, D. Atenolol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Refer kDT 7/e p 567 Diazoxide vasodilator used for hypeension, smooth muscle relaxing activity. Minoxidil vasodilator used for hypeension, also used to treat hair loss. Nicorandil vasodilator used to treat angina. Pinacidil.... Aprikalim. Bimakalim. Cromakalim. Diazoxide. Emakalim. Levcromakalim.', 'role': 'assistant'}]