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': 'All of the following drugs are used in hypertensive crisis except: \nSelect and explain. \nA. Labetalol, B. Pindolol, C. Nitroprusside, D. Nifedipine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. PindololLabetalol is used as hypertensive emergency in pregnancy, nitroprusside is given in patients with aortic dissection. Nifedipine though rarely used, can be given as sublingual therapy for rapid control of blood pressure.', 'role': 'assistant'}]