This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Calcium channel blocker with maximum efficiency on conduction on hea is \nSelect and explain. \nA. Phenylamine, B. Nifedipine, C. Verapamil, D. Diltiazem', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Refer katzung 11e p181 Verapamil, is a medication used for the treatment of high blood pressure, angina, and supraventricular tachycardia. It may also be used for the prevention of migraines and cluster headaches. It is given by mouth or by injection into a vein', 'role': 'assistant'}]