This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anesthesia, Subject name: Pharmacology
Which of the following is the exact mechanism of action of NO 
Select and explain. 
A. Increase in cAMP, B. Increase in CGMP, C. Increase in PGE2, D. Increase in PGD4
B: Increase in CGMP
Answer: B: Increase in CGMP 
Explanation: Nitric oxide is produced by nearly every type of cell in the human body and one of the most impoant molecules for blood vessel health. It's a vasodilator, meaning it relaxes the inner muscles of your blood vessels, causing the vessels to widen. In this way, nitric oxide increases blood flow and lowers blood pressure