Fact 1: Abattery converts chemical energy into electrical energy.

Fact 2: Electricity is a powerful energy source.

Given the two facts above, answer the question "What converts chemical energy into a powerful energy source?" with the following options: 
- animals
 - Green beans
 - an amplifier
 - a battery
 - Light
 - a radio
 - engines
 - a rod


 

    a battery     