You are presented with the question "being preserved under many layers changes vegetation into peat through extreme what?" and the following answer choices: 
- Physical weathering
 - Wet weather
 - heat and mud
 - Time and energy
 - scarce resources
 - heat and pressure
 - heat and vegetation
 - sand and pressure

Now knowing that 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 fossils are typically preserved when they are buried under many layers of sand and mud, choose the best answer.


 

      heat and pressure   