You are presented with the question "what being buried under mud changes peat into coal?" and the following answer choices: 
- a hydraulic system
 - space matter
 - mud shoes
 - Water expanding
 - Physical weathering
 - organic matter
 - flow of electrons
 - insignificant matter

Now knowing that being burried under soil and mud changes peat into coal through extreme heat and pressure in a swamp over a long period of time and peat moss is the organic matter that mixes with soil to form peat, choose the best answer.


 

      organic matter   