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
Which of the following drug is used in the Tensilon test: 
Select and explain. 
A. Methacholine., B. Bethanechol., C. Edrophonium., D. Tacrine.
C: Edrophonium.
Answer: C: Edrophonium. 
Explanation: None