chemical heat magnetic sound
I gave my students this multiple choice question: Francis plugged a toaster into an electric outlet. He put a piece of bread in the toaster and turned the toaster on. While the toaster was on, it changed the electrical energy from the outlet into other forms of energy. Which form of energy toasted the bread?

Only one answer is correct among these 4 choices:
- chemical
- heat
- magnetic
- sound

Could you tell me which one is correct?

heat