Fact 1: Alight bulb requires electrical energy to produce light.

Fact 2: Energy is used by power plants to make electricity.

Given the two facts above, answer the question "What is required for a light bulb to produce light?" with the following options: 
- garden
 - sunlight
 - concrete
 - an electron lens
 - Power plant
 - adding heat
 - Potted plant
 - sun's heat


 

     Power plant    