You are presented with the question "What increases amount of organic matter in dirt?" and the following answer choices: 
- animal transport
 - composure
 - composite
 - decomposition
 - chemical changes
 - fossil fuels
 - composition
 - nutrients

Now knowing that decomposition increases amount of organic matter in soil and dirt, soot or soil is easily distinguishable from mildew, choose the best answer.


 

    decomposition     