Question

when sound is created, it travels to the ear through a
compression.
medium.
rarefaction.
surface.

Explanation:

Sound waves require a medium (such as air, water, or solids) to travel from the source to the ear. Compression and rarefaction are parts of a sound - wave pattern within the medium, not what the sound travels through. A surface is not what sound travels through to reach the ear.

Answer:

B. medium