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: Pharmacology
[{'content': 'Fastest acting receptor/transduction mechanism is: \nSelect and explain. \nA. Adenylyl cyclase – cyclic AMP pathway, B. Phospholipase C–IP3 : DAG pathway, C. Intrinsic ion channel operation, D. Nuclear receptors', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]