This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
[{'content': 'Postural hypotension and failure of ejaculation is most commonly seen in treatment with:(1991) \nSelect and explain. \nA. Guanethedine, B. Minoxidil, C. Propranolol, D. Sodium nitroprusside', 'role': 'user'}, {'content': 'Answer: A \nExplanation: aRef: KDT, 5th ed, p. 514 & 4th ed, p. 551', 'role': 'assistant'}]