Fact 1: Sharpening an object causes that object to change shape.

Fact 2: Another example is the Swiss army knife that contains other objects.

Given the two facts above, answer the question "Sharpening a knife causes it to change what?" with the following options: 
- Energy.
 - energy
 - flavor
 - material
 - color
 - heat
 - shape
 - Joules


 

       shape  