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

The kidneys have several critical functions in maintaining homeostasis within the body. One of their primary roles is the filtration of blood to remove waste products, which is accurately captured in the provided options. They also play a key role in regulating blood pressure through the renin-angiotensin-aldosterone system, which helps manage blood volume and systemic vascular resistance. Additionally, the kidneys maintain electrolyte balance by controlling the levels of essential minerals like sodium, potassium, and calcium in the blood.

However, the kidneys do not secrete enzymes as part of their primary functions. While they do produce hormones such as erythropoietin, which stimulates red blood cell production, the secretion of enzymes is primarily associated with other organs, such as the pancreas, which releases digestive enzymes. Therefore, the response indicating that the secretion of enzymes is not a function of the kidneys is indeed correct, as this does not align with the well-established roles of the renal system.