The image shows a cylinder with a movable wall (partition) and a piston. What properties of matter allow the gas to expand and contract as the wall is removed and the piston moved as depicted in the image?

A
The particles of a gas are close together, they completely fill the volume of the container, they are strongly attracted to each other.
B
The particles of a gas are very far apart, they completely fill the volume of the container, they are weakly attracted to each other.
C
The particles of a gas are close together, they take the shape of the container, they are weakly attracted to each other.
D
The particles of a gas are close together, they take the shape of the container, they are strongly attracted to each other.