Answer: option B. The kinetic energy of gas molecules is directly proportional to the Kelvin temperature of the gas.
Explanation:
The kinetic theory of gases explains the behavior and properties of gases from a molecular perspective.
Specifically and explicity, the kinetic theory of gases states that gases are constituted by particles (molecules) and that the average kinetic energy of the particles is proportional to the absolute temperature (Kelvin scale) of the gas. Furthermore, the temperature of all the (ideal) gases is the same at a given temperature.
Hence, you know that the higher the temperature of the gas, the higher the kinetic energy and the average speed of the molecules.
Other postulates of the kinetic theory of gases are that: i) the volume of the particles is neglectible; ii) the particles do not exhibit intermolecular attraction or repulsion; iii) the particles are in continuous random motion in straight paths, until they collide with other particles or the walls of the vessel, and iv) the collisions are elastic (the energy is conserved).