You are presented with the quiz "What caused the Himalayas to form?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the Himalayas were formed by rock folding" and "folding and metamorphic rock Folding is caused by slow compression and the rock responds by bending". 

So, what's the best answer to the question?


 

  Slow compression         