Fact 1: Being burried under soil and mud changes peat into coal through extreme heat and pressure in a swamp over a long period of time.

Fact 2: Well, a swamp is a type of wetland.

Given the two facts above, answer the question "where does being buried under soil and mud change peat into coal through extreme heat and pressure over a long period of time?" with the following options: 
- watershed
 - alluvial
 - wetland
 - deltas
 - erosion
 - houses
 - earth
 - lakes


 

   wetland      