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': 'drug directly acting on blood vessels is \nSelect and explain. \nA. Hydralizine, B. Verapamil, C. Propranolol, D. Methyldopa', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hydralazine is used with or without other medications to treat high blood pressure. Lowering high blood pressure helps prevent strokes, hea attacks, and kidney problems.Hydralazine is called a vasodilator. It works by relaxing blood vessels so blood can flow through the body more easily. Refer kDT 6/e p547', 'role': 'assistant'}]