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': 'Potassium channel opener with anti–anginal activity is: \nSelect and explain. \nA. Nicorandil, B. Dipyridamole, C. Trimetazidine, D. Oxyfedrine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]