Fact 1: When an electrical circuit is working properly , electrical current runs through that circuit.

Fact 2: Currently computers run on electric circuits and wires.

Given the two facts above, answer the question "Computers run when what is working properly?" with the following options: 
- metal forks
 - an engine
 - lowered energy cost
 - deoxyribonucleic acid
 - plastic switches
 - objects that have mass
 - power ballads
 - electrical circuit


 

        electrical circuit 