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
Cholera toxin - 
Select and explain. 
A. Increases the levels of intracellular cylic GMP, B. Acts through the receptor the opiates, C. Causes continued activation of adenylate cyclase, D. Inhibits the enzyme phosphodiesterase
C: Causes continued activation of adenylate cyclase
Answer: C: Causes continued activation of adenylate cyclase 
Explanation: None