You are presented with the question "What can be used to make debris?" and the following answer choices: 
- erosion
 - rivers
 - a hammer
 - heat
 - wind
 - water pump
 - c-clamp
 - screwdriver

Now knowing that breaking apart rocks can cause debris and sledge hammers can be used to break especially hard ledges of rock, choose the best answer.


 

   a hammer      