This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'The following Potassium channel opener is used in angina \nSelect and explain. \nA. Nicorandil, B. Hydralazine, C. Fasudil, D. Ranolazine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nicorandil, minoxidil, pinacidil are potassium channel openers used in angina which produce hyperpolarization. and causing the vasodilation and reducing the oxygen demand and increase the oxygen supply yo the infracted area. Ref: KD Tripathi 8th ed.', 'role': 'assistant'}]