This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Propanolol is contra-indicated in a patient of angina pectoris who is already receiving: \nSelect and explain. \nA. Nifedipine, B. Aspirin, C. Verapamil, D. Isosorbide mononitrate', 'role': 'user'}, {'content': 'Answer: C \nExplanation: (Ref: KDT 6/e p530) Both verapamil and propanolol decrease the conduction through AV node and their concomitant use can result in hea block.', 'role': 'assistant'}]