Answer: wave
Explanation:
These are the basic definitions and characteristic of the terms given, which show tha the only rigth answer is the second option: wave.
1) Force is an interaction. There are four natural forces: electrostatic, gravity, strong nuclear force and weak nuclear force.
2) Wave: is a sequence of pulses or vibrations that cause the continuous transportation of energy (propagation). There is not transport of mass, only energy.
Some examples of waves are sound waves, electromagnetic waves (light, radio waves, micro waves, infrarred waves, ultraviolet waves).
3) Vacuum: is the absence of matter; empty space. Only electromagnetic waves can travel through vacuum; other waves need a medium to travel.
4) Medium: any matter is a medium: a solid, the air, a liquid, all of them are media through which waves can transport its energy, depending of the wavelength.