i think the answer is D. missed opportunities for internships or travel.
Atrial fibrillations the problem of irregular heartbeats, due to which clots can form inside the veins, and may lead to stroke, and ultimately, heart failure. An anticoagulant is given to such patients, to decrease the chances of occurrence of a heart attack due to blood clot formation.
Using anti-bacterial soaps, Alcohol, Peroxide, and Iodines.