The pulmonary vein is a blood vessel that is responsible for carrying blood to and from the lungs.
Contrary to its name, the pulmonary vein carries oxygenated blood from the lungs to the left auricle of the heart. This is because the blood that flows through the lungs is deoxygenated, and it is the process of gas exchange in the lungs that oxygenates the blood.
After the deoxygenated blood from the body enters the right atrium, it is then pumped into the right ventricle. From there, it is pumped into the lungs via the pulmonary artery, where it is oxygenated. The oxygenated blood then returns to the heart via the pulmonary vein, where it enters the left atrium.
Therefore, the correct statement is that the pulmonary vein carries oxygenated blood from the lungs to the left auricle of the heart.