Fact 1: Faulting of rock in Earth 's crust causes earthquakes.

Fact 2: Earthquakes can cause a tsunami.

Given the two facts above, answer the question "Tsunamis are often cause by what in the earth's crust?" with the following options: 
- waves
 - faulting.
 - flooding
 - pressure
 - friction
 - Movement
 - erosion
 - heat


 

  faulting.       