Question

where does oxygenated blood enter after returning from the lungs? left ventricle right ventricle right atrium left atrium

Explanation:

Oxygenated blood from the lungs returns to the heart via the pulmonary veins. The left atrium is the chamber that first receives this oxygenated blood. The left ventricle then pumps it out to the rest of the body. The right atrium receives de - oxygenated blood from the body, and the right ventricle pumps it to the lungs for oxygenation.

Answer:

Left Atrium