Why are patients experiencing MI given nitroglycerin?

A) It improves the return of venous blood to the heart and helps prevent heart failure.
B) It decreases platelet aggregation and prevents growth of blood clots in the coronary artery.
C) It dissolves the blood clot causing the MI and reduces stresses on the heart.
D) It dilates the narrowed coronary artery and allows more blood into the myocardium.

D