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: Microbiology
The effect of cholera toxin is mediated the stimulation of following second messenger: 
Select and explain. 
A. cAMP, B. cGMP, C. Calcium-calmodulin, D. Acetylcholine
A: cAMP
Answer: A: cAMP 
Explanation: Ans. (a) cAMP