Fact 1: An incandescent light bulb converts electricity into light by sending electricity through a filament.

Fact 2: Electrical energy is also energy.

Given the two facts above, answer the question "What part of a light bulb has energy run through it, converting energy into light?" with the following options: 
- adding heat
 - sun's heat
 - cotton
 - heat energy
 - glass
 - light
 - filaments
 - broken light bulbs


 

       filaments  