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
Which of the following is a selective alpha 2 agonist 
Select and explain. 
A. Clonidine, B. Prazosin, C. Adrenaline, D. Propranolol
A: Clonidine
Answer: A: Clonidine 
Explanation: 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