You are presented with the quiz "What is created when fine particles press down on algae?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "oil is formed by layers of sediment pushing down on decomposing algae" and "earthy sediment of fine particles of rock and soil suspended in and carried by water". 

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


 

       Oil    