Here's a problem to solve: Decomposers are important to the flow of energy in an ecosystem because they

Among the 4 following options, which is the correct answer?

- A: are at the top of every food chain.
 
- B: eat things other organisms do not eat.
 
- C: make up a large portion of the top layer of the soil.
 
- D: break organic material into parts that can be reused.
 