This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'The mechanism of action of Sodium nitroprusside is \nSelect and explain. \nA. Increased cAMP, B. Stimulation of guanylate cyclase, C. Calcium channel blockers, D. Potassium channel blocker', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Sodium nitroprusside acts by releasing nitric oxide(NO). This stimulate guanylate cyclase and results in the elevation of cGMP, which are vasodilators. Refer kDT 6/e p549', 'role': 'assistant'}]