You are presented with the question "what causes the ground to shake?" and the following answer choices: 
- high temperature
 - movements in the earth's crust
 - human migration
 - exposure to cold
 - cloud formation
 - energy of moving objects
 - soil
 - degrees Celsius

Now knowing that an earthquake causes the ground to shake and earthquakes are movements in the Earth's crust, choose the best answer.


 

  movements in the earth's crust       