This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Directly acting cholinergic drug is/are: 
Select and explain. 
A. Pilocarpine., B. Bethanechol., C. Methacholine., D. All of the above.
D: All of the above.
Answer: D: All of the above. 
Explanation: Directly acting

Ach
Pilocarpine
Bethanechol
Methacholine
Carbachol