The only vein that carries oxygenated blood is :

The correct answer is option 3.

Key Points

• The pulmonary vein is the only vein in the human body that carries oxygenated blood. Hence, option 3 is correct.
• It transports oxygen-rich blood from the lungs to the left atrium of the heart.
• This is an exception because veins usually carry deoxygenated blood back to the heart.

Additional Information

• Cystic vein: Drains blood from the gallbladder into the portal vein (deoxygenated).
• Cardiac vein: Carries deoxygenated blood from the heart muscles to the right atrium.
• Hepatic Portal Vein: Carries nutrient-rich but deoxygenated blood from the intestines to the liver.