Answer: B. All the agents listed are vasodilators and act by stimulating the intracellular production of cGMP. The result is that vasodilators are medications that work by dilating blood vessels. As a result, blood flows more easily through the vessels. The heart doesn't have to pump as hard, reducing blood pressure. Vasodilators affect the muscles in the walls of the arteries and veins, preventing the muscles from tightening and the walls from narrowing.