Question

which best describes what is required for any sound wave to travel?
empty space
any medium
solid
liquid

Explanation:

Sound waves are mechanical waves that require a medium (solid, liquid, or gas) to travel as they transfer energy through particle vibrations. Empty space has no particles, so sound can't travel there. "Solid" and "liquid" are specific mediums, but "any medium" includes all possible mediums (solid, liquid, gas) needed for sound wave propagation.

Answer:

B. any medium