Correct Option: C

The liver produces urea and other waste materials and then it pours it all in the right ventricle of the heart for oxygenation. The heart then distributes the blood to various parts of the body. So the impure blood brought by the Hepatic Vein and other blood vessels gets distributed through the aorta. This clearly indicates that hepatic vein carries the largest amount of urea, while the renal vein carries the least.