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: Dead plants provide peat moss.

Given the two facts above, answer the question "What changes into coal when buried under soil and mud?" with the following options: 
- rocks
 - sun
 - animals
 - cellulose
 - moon
 - plants
 - Newton
 - tunicates


 

      plants   