This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Coronary steal phenomenon is caused by which drug ? \nSelect and explain. \nA. Disopyramide, B. Verapamil, C. Nitroglycerine, D. Dipyridamol', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]