What type of wave requires a medium to transfer energy

Mechanical waves.

Explanation:

A mechanical wave is a perturbation on the mechanical properties of the material medium (position, velocity, pressure, etc. ) in which it propagates.

Mechanical waves need a source that creates the perturbation and, a physical medium in which perturbation propagates, the medium can be a gas, a liquid or, a solid.

Some examples are sound, earthquakes and, waves on a guitar string.

he made 11 calls in one day

hi there!

out of the two, (b) precision would be more reasonable.   however, both a and b could be pretty reasonable.

-awesomerepublic   : )