Fact 1: Chlorophyll is used for absorbing light energy by plants.

Fact 2: Chlorophyll is the plant's oxygen producer.

Given the two facts above, answer the question "plants absorb what to produce oxygen?" with the following options: 
- water
 - carbon dioxide
 - light energy
 - The atmosphere
 - water vapor
 - nitrogen
 - air
 - nutrients


 

   light energy      