Fact 1: Biomass is the total mass of organisms at a trophic level.

Fact 2: Most living things are called organisms.

Given the two facts above, answer the question "Biomass is the total mass of living things at each what?" with the following options: 
- trophic level
 - important habitats
 - Energy.
 - food and shelter
 - Power plants
 - animals
 - body water
 - heat energy


 

 trophic level        