Here's a problem to solve: In a healthy forest, dead trees and limbs fall to the ground and decompose. Which of these statements best describes why decomposition is important to a forest ecosystem?

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

- A: Nutrients are released when wood is broken down.
 
- B: Worms produce oxygen used by other organisms.
 
- C: Dead trees provide nest sites for many different species of birds.
 
- D: Water is stored in dead trees and limbs.
 