Answer the following question given this paragraph: 

Ocean waves are among the most impressive waves in the world. They clearly show that waves transfer energy. In the case of ocean waves, energy is transferred through matter. But some waves, called electromagnetic waves, can transfer energy without traveling through matter. These waves can travel through space. You can read more about electromagnetic waves in the chapter "Electromagnetic Radiation. " Waves that transfer energy through matter are the focus of the present chapter. These waves are called mechanical waves.


Q: What term describes waves that transfer energy through matter?

 Choices:

- mechanical currents

- temperature waves

- energy currents

- mechanical waves

A:
mechanical waves
