Fact 1: An earthquake causes the ground to shake.

Fact 2: Earthquakes are caused by movement of the tectonic plates.

Given the two facts above, answer the question "The ground shakes as a result of the movement of what?" with the following options: 
- Earth's core
 - Electrical energy
 - tectonic plates
 - kinetic energy
 - vehicles
 - electromagnetic energy
 - earth
 - magnetics


 

   tectonic plates      