This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pharmacology
[{'content': 'Nitric oxide acts via: \nSelect and explain. \nA. cAMP, B. cGMP, C. Ca, D. K', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (B) cGMP(Ref: Katzung 13th/e p329-330)Nitric oxide stimulates guanylate cyclase, that increases cGMP. Later is a powerful vasodilator.', 'role': 'assistant'}]