Answer:
The correct answer is B.
Explanation:
Nitroglycerin is a medication that produces relaxation of vascular smooth muscle. This happens because nitroglycerin is converted into nitric oxide (NO) in the body. NO then activates the enzyme guanylyl cyclase, which converts guanosine triphosphate into guanosine 3',5'-monophosphate (cGMP). cGMP then activates many protein kinase-dependent phosphorylations, resulting in the dephosphorylation of myosin light chains within smooth muscle fibers.
This causes the relaxation of smooth muscle and as a result blood vessels dilatate.
