Cooling the Gas in a Container Lowers the Pressure Because

Cooling the gas in a container lowers the pressure because

A) there are less atoms in the container.
B) the potential energy increases in the container.
C) there are less collisions with the wall of the container.
D) the molecules' impact with the wall are less energetic.
E) the molecules slow down so both force and number of collisions with the walls is reduced.