Being burried under soil and mud changes vegetation into peat through extreme heat and pressure in a swamp over a long period of time, and peat moss from bogs is also useful in gardens and as an alternative fuel source. Given these facts, what does vegetation change into after being buried under soil among the following options:
- desert
 - space
 - grass
 - blankets
 - bushes
 - time
 - roots
 - fuel


 

        fuel 