Which is not a function of the kidneys? regulation of blood pressure regulation of acid-base balance removal of wastes from the blood regulation of lymphocyte production regulation of erythrocyte production?

The correct answer is regulation of lymphocyte production.  

Kidneys have a function in:
·     regulation of blood pressure (through the regulation of the volume of blood in the body);
·     regulation of acid-base balance (by excreting H+ into the urine and reabsorbing HCO3- from the urine);
·     removal of wastes from the blood (through the urine);
·     regulation of erythrocyte production (producing erythropoietin hormone).