You are presented with the question "What becomes something that is burned to generate heat?" and the following answer choices: 
- glass
 - dead vegetation
 - Fuel cells
 - preserved vegetation
 - Electrical energy
 - hydrogen and oxygen
 - clouds
 - electricity

Now knowing that coal is used for generating heat by burning and dead vegetation settles and becomes peat, a precursor of coal, choose the best answer.


 

  dead vegetation       