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: Physiology
If there is a Gs alfa subunit gain-of-function mutation, this results in: 
Select and explain. 
A. Decreased cAMP, B. Decreased IP3, C. Increased GTPase activity, D. Increased cAMP
D: Increased cAMP
Answer: D: Increased cAMP 
Explanation: D i.e. Increased cAMPGs-a subunit gain would cause increased adenyl cyclase level - ultimately resulting in increased c-AMP levelQ, (because adenyl cyclase conves ATP to c-AMP).