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': 'Potassium channel opener with anti-anginal activity is: \nSelect and explain. \nA. Nicorandil, B. Dipyridamole, C. Dofetilide, D. AMIODARONE', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nicorandil opens ATP-dependent K+ channels causing aerial dilatation thus increasing afterload-potassium channel opener-used for angina Amiodarone and dofetilide are potassium channel blockers- class 3 antiarrhythmic agents REF.Essentials of Medical Pharmacology KD Tripathi 8th ed.', 'role': 'assistant'}]