This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Pharmacology
Sodium nitroprusside is metabolized to form an active metabolite. This active metabolite of sodium nitroprusside act activation of:- 
Select and explain. 
A. Phospholipase A, B. Phospholipase C, C. Guanylate cyclase, D. Protein kinase C
C: Guanylate cyclase
Answer: C: Guanylate cyclase 
Explanation: Nitoprusside and nitrates act by production of NO (nitric oxide). NO stimulates guanylate cyclase in smooth muscles which leads to formation of cGMP. cGMP act on smooth muscles to cause vasodilation.