You are presented with the question "The Himalayas were formed by what?" and the following answer choices: 
- fissures of hot, acidic water
 - Movement of an air mass
 - movements in the earth's crust
 - movement of tectonic plates
 - remains of prehistoric life
 - tectonic plates coliding
 - air mass over Earth's surface
 - ductile rock deformation

Now knowing that the Himalayas were formed by rock folding and folds are examples of ductile rock deformation, choose the best answer.


 

        ductile rock deformation 