Fact 1: An earthquake causes the ground to shake.

Fact 2: Seismic waves are produced by earthquakes.

Given the two facts above, answer the question "Seismic waves cause what to shake?" with the following options: 
- earth
 - body water
 - wind
 - tremors
 - sunlight
 - the ground
 - Sediment
 - rocks


 

      the ground   