You are presented with the question "what has forced extered on it if kicked?" and the following answer choices: 
- animals
 - mussels
 - control boxes
 - heat energy
 - energy barrier
 - a hydraulic system
 - activation energy
 - kinetic energy

Now knowing that if an object is kicked then force is exerted on that object and control boxes are objects, choose the best answer.


 

   control boxes      