You are presented with the quiz "Burning garbage can be used to produce what?" But you don't know the answer, so you turn to your teacher to ask for hints. He says that "biofuel is used to produce electricity by burning" and "among the energy sources referred to as biofuels is garbage". So, what's the best answer to the question?

Options:
*warmth.
*heat energy.
*a slowing of global warming.
*gold.
*electricity.
*adding heat.
*mutant protection.
*carbon dioxide.
The answer is:
electricity