Fact 1: High pressure systems cause clear weather.

Fact 2: High barometric pressure indicates clear weather.

Given the two facts above, answer the question "What causes clear weather?" with the following options: 
- our nearest star
 - electromagnetic energy
 - looseness of dirt or compost
 - Animal survival
 - The area was once underwater
 - evaporation
 - barometric pressure
 - windpower operated machines


 

       barometric pressure  