Fact 1: Alight bulb is used for seeing in the dark.

Fact 2: Light is emitted by a light bulb.

Given the two facts above, answer the question "What is emitted light used for ?" with the following options: 
- electricity
 - To see in the dark.
 - activation energy
 - heat energy
 - kinetic energy
 - an electron microscope
 - major threat to health
 - Electrical energy


 

  To see in the dark.       