With increase in temperature, the rate of leaching increases, because the

ANS:A - diffusivity of solute increases.

With an increase in temperature, the rate of leaching increases because the diffusivity of solute increases. When temperature rises, the kinetic energy of molecules in the system also increases. This increased energy leads to greater movement and collisions among the solvent and solute molecules. As a result, the solute molecules diffuse more rapidly through the solvent, leading to a higher rate of leaching. Therefore, the correct option is: diffusivity of solute increases.