Fact 1: Drought is when amount of precipitation decreases.

Fact 2: During drought, water supply reduced.

Given the two facts above, answer the question "Reduced water supply occurs when what amounts decrease?" with the following options: 
- precipitation
 - visibility
 - fog
 - sound
 - In the winter
 - Dehydration
 - deforestation
 - salinity


 

 precipitation        