Question

extra salt is reabsorbed in the ascending limb of the loop of henle by
active transport.
diffusion.
osmosis.
rewatch submit

Explanation:

The ascending limb of the loop of Henle reabsorbs salts (e.g., Na⁺, Cl⁻) against their concentration gradient, which requires energy. This process is active transport. Diffusion (passive down gradient) and osmosis (water movement) do not fit.

Answer:

active transport.