You are presented with the question "Burning which of these increases carbon in the atmosphere?" and the following answer choices: 
- wind energy
 - natural gas
 - green manures
 - Greenhouse gases
 - solar energy
 - Conifers
 - engines
 - oxygen

Now knowing that burning fossil fuels increases the carbon in the atmosphere and natural gas is the cleanest of the fossil fuels, choose the best answer.


 

  natural gas       