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
Which of the following drug is a potassium channel opener 
Select and explain. 
A. Nifedipine, B. Minoxidil, C. Enalapril, D. Atenolol
B: Minoxidil
Answer: B: Minoxidil 
Explanation: 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.