Answer : Option B) All collisions between particles are perfectly elastic.
Explanation : Gases consits of molecules which are compressible because the gas particles which have a small volume compared to the container.
The collisions are perfectly elastic because when gases are left alone in a container they don't seem to lose energy and do not spontaneously get converted into a liquid, also energy is not lost during collisions.
In the diagram given above one can interpret that the gaseous molecules are in random motion inside the container and when they collide with other molecule of gas they do not lose energy. Therefore, this shows perfectly elastic collisions.
