Final answer:
The nurse should reinforce smoking cessation as the priority intervention among the modifiable cardiac risk factors. Smoking is a major risk factor for cardiovascular disease, as it damages blood vessels, increases blood pressure, and decreases oxygen levels in the blood.
Step-by-step explanation:
The nurse should reinforce smoking cessation as the priority intervention among the modifiable cardiac risk factors. Smoking is a major risk factor for cardiovascular disease, as it damages blood vessels, increases blood pressure, and decreases oxygen levels in the blood. By quitting smoking, individuals can significantly reduce their risk of developing heart disease.