Answer the following question given this paragraph: 

Another example of transverse waves occurs with earthquakes. The disturbance that causes an earthquake sends transverse waves through underground rocks in all directions from the disturbance. Earthquake waves that travel this way are called secondary, or S, waves. An S wave is illustrated in Figure below .


Q: Earthquake waves that travel trhough underground rocks in all directions are known as?

 Choices:

- tertiary waves

- primary waves

- typical waves

- secondary waves

A:
secondary waves
