You are presented with the question "Sharpening a knife causes it to change what?" and the following answer choices: 
- Energy.
 - energy
 - flavor
 - material
 - color
 - heat
 - shape
 - Joules

Now knowing that sharpening an object causes that object to change shape and another example is the Swiss army knife that contains other objects, choose the best answer.


 

       shape  