Answer:
D. maintenance of blood glucose levels
Step-by-step explanation:
The primary function of the urinary system is to get rid of metabolic waste. The metabolic waste is excreted out of the body in the form of urine. Glucose is not part of the urine of a normal human with no medical conditions. Glucose is reabsorbed during tubular re-absorption and is sent back to the blood.
Antagonistic effects of insulin and glucagon maintain blood glucose levels. Urinary system does not perform this function.