Question

multiple choice question
what is the primary function of the kidneys?

o eliminate proteins
o regulate composition and volume of extracellular fluid
o control the functioning of the liver, pancreas, and spleen
o produce red blood cells

Explanation:

The kidneys filter blood, remove waste products and excess water, and help maintain the balance of electrolytes and fluid in the body. This is related to regulating the composition and volume of extracellular fluid. Proteins are not primarily eliminated by the kidneys (they are usually reabsorbed if small - sized proteins are filtered). The kidneys do not control the functioning of the liver, pancreas, and spleen. The production of red blood cells is mainly regulated by erythropoietin (produced by the kidneys to a certain extent, but the primary site of red - blood - cell production is the bone marrow).

Answer:

regulate composition and volume of extracellular fluid