You are presented with the question "Biomass is the total mass of living things at each what?" and the following answer choices: 
- trophic level
 - important habitats
 - Energy.
 - food and shelter
 - Power plants
 - animals
 - body water
 - heat energy

Now knowing that biomass is the total mass of organisms at a trophic level and most living things are called organisms, choose the best answer.


 

 trophic level        