This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Impotence is most commonly caused by which antihypeensive agent- \nSelect and explain. \nA. Calcium channel blocker, B. ACE inhibitors, C. ATI receptor antagonists, D. b-blockers', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., b - blockers Amongst the antihypeensive agents the thiazide diuretics and b-blockers have been implicated most frequently. o Calcium channel blockers and ACE inhibitors are less frequently cited.", 'role': 'assistant'}]