Fact 1: Sunlight and rain can cause a rainbow.

Fact 2: All deserts have very little rain.

Given the two facts above, answer the question "Where do rainbows rarely appear?" with the following options: 
- the Great Barrier Reef
 - Nurseries of the ocean.
 - over the mountains
 - over the valleys
 - summer end
 - over the plains
 - swamp vegetation
 - over the deserts


 

        over the deserts 