You Are Transporting a Patient Who Had an Episode of Chest

You are transporting a patient who had an episode of chest pain. On scene you assisted him in taking his nitroglycerin, which completely alleviated the chest pain. En route to the hospital, he asks you why the nitroglycerin takes the chest pain away. Your response would be:

A) "It causes the heart rate to decrease, which relaxes it and decreases pain."
B) "It has a sedative effect on the brain, making you less aware of the pain."
C) "It dilates the blood vessels, which decreases the workload of the heart."
D) "It causes the body to relax, decreasing the need for oxygen."