You are presented with the quiz "Where can peat, buried under soil and mud and through extreme heat and pressure, change into coal?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says 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 "marshes and swamps are wetlands". 

So, what's the best answer to the question?


 

      wetlands     