You are presented with the question "Propellers are on some airplanes primarily to give" and the following answer choices: 
- stability
 - protection from bird strikes
 - speed
 - motion
 - engine cooling
 - energy
 - noise cancellation
 - power

Now knowing that producing thrust causes something to move and airplanes create thrust using propellers, jet engines , or rockets , choose the best answer.


 

    motion     