Deoxygenated blood enters the heart via specific vessels

Steps:

• Identify deoxygenated blood: Oxygen-poor blood returns from the body or lungs to the heart.
• Recall heart connections: The heart receives blood through veins and sends it out through arteries.
• Check vena cava: Superior and inferior vena cava bring deoxygenated blood from the body to the right atrium.
• Check pulmonary artery: Carries deoxygenated blood from the right ventricle to the lungs.

Why C is correct:

• Vena cava and pulmonary artery both transport deoxygenated blood directly to or from the heart's right side, per circulatory system definitions.

Why the others are wrong:

• A: Aorta carries oxygenated blood from the left ventricle to the body.
• B: Aorta carries oxygenated blood; pulmonary vein carries oxygenated blood from lungs to left atrium.
• D: Pulmonary vein carries oxygenated blood from lungs to the heart.

Final answer: C