closer together than air molecules. more easily moved than air molecules. moving faster than air molecules. larger than air molecules.
I gave my students this multiple choice question: Sound is able to travel faster in solids than in air because the molecules in a solid are

Only one answer is correct among these 4 choices:
- closer together than air molecules.
- more easily moved than air molecules.
- moving faster than air molecules.
- larger than air molecules.

Could you tell me which one is correct?

closer together than air molecules.