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
True about G-protein receptor complex: 
Select and explain. 
A. It interacts transmembrane domain., B. GTP to GDP, C. Adenyl cyclase activation leads to increased cAMP, D. All
D: All
Answer: D: All 
Explanation: A i.e. It interacts transmembrane domain; B i.e. GTP to GDP; C i.e. Adenyl cyclase activation leads to increased cAMP