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': 'All the following mediate their action using cAMP as second messenger except: \nSelect and explain. \nA. Coicotropin, B. Dopamine, C. Glucagon, D. Vasopressin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Vasopressin', 'role': 'assistant'}]