Why is reabsorption of water important in nephrons?

Correct answer: To maintain water balance in the body

The governing concept is selective reabsorption during urine formation. Filtration at the nephron may place water and useful dissolved substances into the filtrate. The renal tubule reabsorbs an appropriate amount of water, depending on the body's needs, and returns it to the blood. This prevents excessive water loss and helps maintain internal water and salt balance. The other options are unrelated to kidney function, so A is correct.