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
Propanolol is contra-indicated in a patient of angina pectoris who is already receiving: 
Select and explain. 
A. Nifedipine, B. Aspirin, C. Verapamil, D. Isosorbide mononitrate
C: Verapamil
Answer: C: Verapamil 
Explanation: (Ref: KDT 6/e p530) Both verapamil and propanolol decrease the conduction through AV node and their concomitant use can result in hea block.