ANS:D - decrease in the viscosity of liquids and increase in that of gases.

Increase in temperature, in general, results in the decrease in the viscosities of both liquids & gases. This phenomenon can be explained by considering the molecular motion within the substance. When temperature increases, the average kinetic energy of the molecules increases, causing them to move more rapidly. In liquids, this increased molecular motion results in weaker intermolecular forces and greater molecular mobility, leading to reduced viscosity. Similarly, in gases, higher temperatures lead to increased molecular velocities, which decreases the frequency of molecular collisions and lowers the resistance to flow, also resulting in decreased viscosity. Therefore, an increase in temperature generally leads to a decrease in viscosity for both liquids and gases.