If something studied by Michael Faraday can cause objects to repel each other, then what can cause objects to repel each other?

Answer choices:
- Something studied by Michael Faraday
 - Mutagenic chemicals
 - a hemisphere is tilted away from the sun
 - fissures of hot, acidic water
 - chemical to mechanical energy
 - absorb light energy
 - electromagnetic energy
 - Slowing the transfer of heat

 

 Something studied by Michael Faraday         