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
Action of alpha 2 and b1 receptors on adenyl cyclase 
Select and explain. 
A. Stimulate; Stimulate, B. Stimulate; Inhibit, C. Inhibit; Inhibit, D. Inhibit; Stimulate
D: Inhibit; Stimulate
Answer: D: Inhibit; Stimulate 
Explanation: Beta receptors are GsPCR -so increase adenyl cyclase activity.alpha 1 -g1 pcr,alpha 2 GiPCR-decrease adenyl cyclase activity Ref: KD Tripathi 8th ed.