This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: A.N.S., Subject name: Pharmacology
[{'content': 'Which of the following is an selective a-2 antagonist? \nSelect and explain. \nA. Prazosin, B. Labetalol, C. Yohimbine, D. Butoxamine', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Yohimbine o Selective a2-antagonists are yohimbine and idozoxon.Important a adrenergic blocking drugso Non equilibrium (irreversible) type - Phenoxybenzamineo Equilibrium (reversible) typeA. Non selective - Ergotamine, Ergotoxine, Tolazoline, Phentolamine, Chlorpromazine,B. a1 selective - Prazosin, Terazosin, Doxazosin, Trimazosin, Alfuzosin, Indoramine, Urapidil, Tamsulosine.C. a2 selective - Yohimbine, Idazoxan", 'role': 'assistant'}]