You are presented with the question "What is required for a light bulb to produce light?" and the following answer choices: 
- garden
 - sunlight
 - concrete
 - an electron lens
 - Power plant
 - adding heat
 - Potted plant
 - sun's heat

Now knowing that alight bulb requires electrical energy to produce light and energy is used by power plants to make electricity, choose the best answer.


 

     Power plant    