Question

if a substance has freely moving molecules and does not have a fixed volume or a fixed shape, it must be a solid liquid gas

Explanation:

Solids have fixed shape and volume with closely - packed molecules. Liquids have a fixed volume but take the shape of the container and have more mobile molecules than solids. Gases have freely moving molecules and neither a fixed volume nor a fixed shape as they expand to fill the container.

Answer:

C. gas