You are presented with the question "what is used as an energy source to electrical outlets" and the following answer choices: 
- engines
 - rain
 - adding heat
 - copper
 - energy
 - rays or beams
 - wires
 - electricity

Now knowing that electricity is used as an energy source by electrical devices and once a device is plugged into electrical outlets, it can communicate with other devices, choose the best answer.


 

        electricity 