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
Nitric oxide acts via: 
Select and explain. 
A. cAMP, B. cGMP, C. Ca, D. K
B: cGMP
Answer: B: cGMP 
Explanation: Ans. (B) cGMP(Ref: Katzung 13th/e p329-330)Nitric oxide stimulates guanylate cyclase, that increases cGMP. Later is a powerful vasodilator.