Fact 1: Aflashlight requires a source of electricity to produce light.

Fact 2: Electrical energy is also energy.

Given the two facts above, answer the question "What requires a source of energy to produce light?" with the following options: 
- sunlight
 - cactuses
 - cakes
 - pies
 - heterotrophs
 - flashlights
 - batteries
 - most cephalopods


 

      flashlights   