You are presented with the question "acid rain is caused by burning what?" and the following answer choices: 
- lung
 - grass
 - oil
 - Cars
 - Coal
 - peat
 - nitrogen
 - food

Now knowing that gases from burning coal and oil dissolving in water in the atmosphere causes acid rain and acid rain is caused by the burning of fuels such as oil and coal, choose the best answer.


 

   oil      