Fact 1: The Himalayas were formed by rock folding.

Fact 2: An earthquake may cause folding of the layers.

Given the two facts above, answer the question "The Himalayas were formed by what?" with the following options: 
- earthquakes
 - snowfall
 - chemical changes
 - movement
 - fires
 - graptolites
 - rain
 - calcite


 

 earthquakes        