This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
[{'content': 'A drug that blocks the hea rate effect of a slow intravenous infusion of Phenylephrine is \nSelect and explain. \nA. Atenolol, B. Prazosin, C. Atropine, D. Propranolol', 'role': 'user'}, {'content': 'Answer: C \nExplanation: .', 'role': 'assistant'}]