Fact 1: The vanes rotating in an electric fan causes air to move.

Fact 2: Wind is a movement of air, and air is invisible.

Given the two facts above, answer the question "The vanes rotating in an electric fan causes what?" with the following options: 
- speed
 - water
 - earth
 - fire
 - heat
 - Lift
 - wind
 - motion


 

       wind  