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': 'Aerial dilator used in treatment of congestive hea failure are All except \nSelect and explain. \nA. Hydralizine, B. Nifedipine, C. Prazosin, D. Nitrates', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Refer kDT 6/e p540 Nitrates are primaryly venodilators. Hydralizine and nifedipine dilate mainly aerials whereas ACE inhibitors an alpha blockers dilate both aerioles as well as veins', 'role': 'assistant'}]