Both mechanical and electromagnetic waves a. have compressions and rarefactions b. oscillate in the same direction as the wave motion c. transmit energy d. require a medium for transfer

The correct answer is option C.

That is both mechanical and electromagnetic waves transmit energy.

Mechanical waves required a medium like air to travel but electromagnetic waves doesn't require a medium. Mechanical wave is like sound that travel through air while electromagnetic wave is like light that don't require a medium to travel. But both types of waves transfer energy in a wave-like manner that is both transmit energy.