Fact 1: Freshwater biomes have water that contains little or no salt.

Fact 2: Another name for salt is sodium.

Given the two facts above, answer the question "Freshwater biomes contain water that contains little to no what?" with the following options: 
- cations
 - Acids
 - Nutrients
 - sodium
 - Pollution
 - animals
 - plants
 - water


 

    sodium     