Which one of the following environments will sound not travel through?

a. Gas

b. Solid

c. Liquid

d. Vacuum

Sound waves require the vibration of particles in order to be propagated, in a vacuum as there are no particles the waves are unable to travel, which is why no sound can be heard in space.

The answer is d. Vacuum

Sound waves need a molecul to travel through. Gas, solid, annd liquid provide that medium.

But vacuum is just an empty space withour any moleculs in it.

Thats why in space, no one can hear you scream. Because it simply not physicsly possible