This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General, Subject name: Physiology
[{'content': 'Mechanism of action of NO is - \nSelect and explain. \nA. Through protein kinase C, B. Through IP3-DAG system, C. Through cGMP, D. Through intracellular receptors', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Through cGMP * NO acts through group IIB hormonal mechanisms, i.e. through cGMP as the second messenger.", 'role': 'assistant'}]