A nurse is caring for a patient with a confirmed myocardial infarction. The physician orders morphine for pain relief. What is the primary action of morphine in the management of MI?

It prevents the formation of blood clots in the coronary arteries.

It reduces anxiety and decreases myocardial oxygen demand.

It dilates the coronary arteries and increases oxygen delivery.

It improves blood pressure by causing vasoconstriction.