You are presented with the question "An electric car requires what to operate?" and the following answer choices: 
- radiation shielding
 - hydrogen and oxygen
 - electromagnetic energy
 - gasoline
 - direct energy
 - heat energy
 - a closed circuit
 - oxygen

Now knowing that powering an electrical device with a battery requires a path for electricity to flow through a closed circuit and electric cars have big batteries instead of engines, choose the best answer.


 

       a closed circuit  