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
[{'content': 'True about G-protein receptor complex: \nSelect and explain. \nA. It interacts transmembrane domain., B. GTP to GDP, C. Adenyl cyclase activation leads to increased cAMP, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A i.e. It interacts transmembrane domain; B i.e. GTP to GDP; C i.e. Adenyl cyclase activation leads to increased cAMP', 'role': 'assistant'}]