Fact 1: Sunlight and rain can cause a rainbow.

Fact 2: Liquid precipitation is measured with a rain gauge.

Given the two facts above, answer the question "What can cause a rainbow?" with the following options: 
- photosyntehsis
 - tornadoes
 - sun and hot weather
 - snowfall and fog
 - chemical messengers
 - sun and liquid precipitation
 - algae and plants
 - photosynthetic pigments?


 

      sun and liquid precipitation   