You are presented with the quiz "Decayed vegetation turns to what over a period of time?" 

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 vegetation into peat through extreme heat and pressure in a swamp over a long period of time" and "often, the soil consists of mats of very acidic, semi-decayed vegetation, such as peat". 

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


 

   peat        