Answer the following question given this paragraph: 

Like density, the pressure of the air decreases with altitude. There is less air pressing down from above the higher up you go. Look at the bottle pictured below ( Figure below ). It was drained by a hiker at the top of a mountain. Then the hiker screwed the cap on the bottle and carried it down to sea level. At the lower altitude, air pressure crushed it. Can you explain why?.


Q: How does air pressure change as altitude increases?

 Choices:

- goes up and down

- stays the same

- It increases

- it decreases

A:
it decreases
