If we increase the temperature of gases, their viscosity

Explanation

The viscosity of gases increases with an increase in temperature. This is because, at higher temperatures, gas molecules have more kinetic energy, leading to more frequent and forceful molecular collisions. This increased interaction between molecules results in higher resistance to flow, which is observed as increased viscosity. On the other hand, in liquids, viscosity decreases with a rise in temperature due to weakening intermolecular forces. The option that states 'Decreases' is correct for liquids, not gases. The option 'Remains constant' is incorrect as gas viscosity changes with temperature. 'None of these' is incorrect because the correct answer is provided among the options.