This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
[{'content': 'Which of the following is a selective alpha 2 agonist \nSelect and explain. \nA. Clonidine, B. Prazosin, C. Adrenaline, D. Propranolol', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref: HL Sharma 3rd ed pg No:178 Clonidine, methyldopa, apraclonidine, tizanidine are alpha 2 agonists they are centrally action- used to decrease BP, cause muscle relaxation etc', 'role': 'assistant'}]