You are presented with the question "What does air movement cause around the earth?" and the following answer choices: 
- air pressure
 - waterfalls
 - Temperature
 - scattered light
 - waste products
 - global warming
 - friction
 - puddles

Now knowing that the movement of an air mass over Earth 's surface causes local weather changes and altitude and weather systems can change the air's pressure, choose the best answer.


 

 air pressure        