This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ANS, Subject name: Pharmacology
Which of the following drug possess maximum action on nicotinic receptors? 
Select and explain. 
A. Bethanechol, B. Carbachol, C. Pilocarpine, D. Methacholine
B: Carbachol
Answer: B: Carbachol 
Explanation: Drugs Acts on Action Indication Pilocarpine M3, Pupil Miosis Glaucoma Bethanechol M3, Bladder Increase outflow Atonic bladder Carbachol Nicotinic , muscarinic Methacholine M2 Cardiac suppression Tachycardia, Arrhythmias