Concept:The pulmonary artery is the only vessel that carries de-oxygenated blood from the heart to the lungs for gas exchange.
Explanation:De-oxygenated blood contains high levels of carbon dioxide (
CO2).
This blood returns to the heart and enters the right ventricle.
From the right ventricle, it is pumped through the pulmonary artery into the lungs.
In the lungs, carbon dioxide is removed and oxygen is absorbed.
The renal vein carries blood from the kidneys, not to the lungs.
The hepatic portal vein carries nutrient-rich blood from the digestive organs to the liver.
The pulmonary vein carries oxygenated blood from the lungs back to the heart.
Therefore, only the pulmonary artery transports de-oxygenated blood to the lungs.
Answer:C. pulmonary artery