This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
Carbachol acts as 
Select and explain. 
A. Agonist for M2 receptors, B. Agonist for M3 receptors, C. Agonist for M1 receptors, D. Antagonist for M3 receptors
B: Agonist for M3 receptors
Answer: B: Agonist for M3 receptors 
Explanation: M2 agonist: MethacholineM3 agonists: Carbachol, bethanecholRef: Katzung 12th Ed.Pg 100