The direction of blood flow through the heart is best described by which of these?

A. Aorta- right atrium-right ventricle-lungs-pulmonary vein→ left atrium→ left ventricle→ vena cava: This sequence is incorrect because blood does not flow from the aorta to the right atrium; rather, the aorta carries oxygenated blood from the left ventricle to the body. The vena cava brings deoxygenated blood into the right atrium. B. Vena cava-right atrium-right ventricle-lungs-pulmonary artery-left atrium-left ventricle: This sequence is incorrect because the blood does not flow from the lungs directly into the left atrium via the pulmonary artery; instead, blood from the lungs returns to the left atrium via the pulmonary veins. C. Right atrium → right ventricle → pulmonary vein → lungs → pulmonary artery → left atrium → left ventricle: This sequence is incorrect because the pulmonary veins carry oxygenated blood from the lungs to the left atrium, not to the right ventricle. D. Right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle: This is the correct sequence of blood flow through the heart. Blood flows from the right atrium to the right ventricle, then to the pulmonary artery, which carries it to the lungs for oxygenation. After oxygenation, blood returns to the left atrium via the pulmonary veins and then flows into the left ventricle before being pumped out to the body through the aorta.