Fact 1: Crumple means change shape from smooth into compacted by physical force.

Fact 2: Crumple the foil then carefully reopen it.

Given the two facts above, answer the question "What is used to scrunch up foil?" with the following options: 
- tin
 - awl
 - parchment paper
 - an external framework
 - Physical force
 - energy barrier
 - hard outer covering
 - Evaporation


 

     Physical force    