You are presented with the question "Which of the following can cause objects to repel each other?" and the following answer choices: 
- electromagnetic energy
 - mass
 - Electrical energy
 - gravitation
 - electrical currents
 - photosynthesis
 - the Great Barrier Reef
 - electricity

Now knowing that magnetism can cause objects to repel each other and electrical currents cause magnetic fields, choose the best answer.


 

     electrical currents    