You are presented with the question "What part of a light bulb has energy run through it, converting energy into light?" and the following answer choices: 
- adding heat
 - sun's heat
 - cotton
 - heat energy
 - glass
 - light
 - filaments
 - broken light bulbs

Now knowing that an incandescent light bulb converts electricity into light by sending electricity through a filament and electrical energy is also energy, choose the best answer.


 

       filaments  