Which of the following is NOT a function of the liver?

The liver is a vital organ with several key functions, including bile production, removal of old red blood cells, and waste elimination.

Producing bile is one of the liver's primary functions, as bile is essential for the digestion and absorption of fats. The liver also plays a critical role in the lifecycle of red blood cells; it helps remove old or damaged red blood cells from circulation. The breakdown of these cells also contributes to the production of bilirubin, which is processed by the liver.

Eliminating waste from the body is another crucial function of the liver. It detoxifies various metabolites, processes drugs, and removes harmful substances, ensuring that the blood is clean before it returns to circulation.

In contrast, the secretion of renin is not a function performed by the liver. Renin is an enzyme produced by the kidneys that regulates blood pressure. The kidneys sense changes in blood pressure and release renin to initiate a cascade of events that ultimately leads to an increase in blood pressure when necessary. Thus, considering these functions, the statement regarding the liver secreting renin when blood pressure is elevated is incorrect, further confirming that it does not partake in this process.