WILL GIVE BRAINLIEST! If a system stores kinetic energy, which choice must be true?

The molecules, atoms, and/or subatomic particles must be exerting forces on each.
The molecules, atoms, and/or subatomic particles must be at rest.
The molecules, atoms, and/or subatomic particles must be within earth’s gravitational field.
The molecules, atoms, and/or subatomic particles must be moving.