When the blood reaches the glomerular capillaries through the afferent arterioles, due to the filtering effect of the glomerulus and the inner wall of the renal capsule, some substances in the plasma, such as water, inorganic salts, glucose, urea, etc., can be filtered into the renal capsule cavity to form protourine, except protein of blood cells and macromolecules. When the original urine flows through the renal tubule, substances useful to the human body will be reabsorbed by the renal tubule, including all glucose, most water and some inorganic salts. These substances enter the capillaries outside the renal tubules and are sent back to the blood. The remaining substances, such as urea, some inorganic salts and water, flow out of the renal tubules to form urine. Therefore, although healthy people form about 150 liters of raw urine every day, the urine discharged every day is only about 1.5 liters, which is due to the reabsorption of renal tubules, which reabsorbs most of the water into the blood.
So choose: B.