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': 'Nitroglycerin cause all except \nSelect and explain. \nA. Hypotention and bradycardia, B. Methamoglobinemia, C. Hypotention and tachycardia, D. Vasodilatation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Refer katzung 11e p 265 KDT 6/e p524 Nitrates most commonly used antianginal drugs. These act by decreasing delivery of nitric oxide in the blood vessels leading to vasodilatation.', 'role': 'assistant'}]