Fact 1: Temperature falls from lower to higher altitudes.

Fact 2: If the weather is warm, their temperature rises.

Given the two facts above, answer the question "What falls from lower to higher altitudes?" with the following options: 
- warm weather
 - sun's heat
 - rainfall
 - heat energy
 - kinetic energy
 - water vapor
 - colder and wetter
 - Greenhouse gasses


 

 warm weather        