You are presented with the question "What is created when fine particles press down on algae?" and the following answer choices: 
- DDT
 - More algae
 - More fine particles
 - smog
 - urea
 - Water
 - Oil
 - gas

Now knowing 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, choose the best answer.


 

       Oil  