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

The production of bile is primarily a function of the liver, not the kidneys. The kidneys are vital organs responsible for several key processes that maintain homeostasis within the body. These include the formation of urine, which is essential for waste elimination and fluid balance; the regulation of blood pressure through the renin-angiotensin system; and the balancing of electrolytes, which is crucial for nerve and muscle function, as well as overall cellular activity. Recognizing these distinct roles of the kidneys highlights why the production of bile, associated exclusively with liver function, stands out as the correct answer to this question.