When electrical energy is converted into thermal energy, which of the following must be true?

Only the amount of electrical energy changes.
Only the amount of thermal energy changes.
The total amount of thermal energy plus electrical energy changes.
The total amount of thermal energy plus electrical energy doesn't change.

Question

When electrical energy is converted into thermal energy, which of the following must be true?  

Only the amount of electrical energy changes.
Only the amount of thermal energy changes.
The total amount of thermal energy plus electrical energy changes.
The total amount of thermal energy plus electrical energy doesn't change.

anonymous · Answer

Ok I know it's the fourth one but why

mwhit2101 · Answer

"D"