Answer the following question given this paragraph: 

Mechanical waves are waves that transfer energy through matter, called the medium. Mechanical waves start when a source of energy causes a disturbance in the medium. Types of mechanical waves include transverse, longitudinal, and surface waves.


Q: What type of waves start when a source of energy causes a disturbance in the medium?

 Choices:

- fluid waves

- mechanical currents

- magnetic waves

- mechanical waves

A:
mechanical waves
