The heat comes from the Sun. The heat comes from pools of underground water. The heat comes from deep within Earth. The heat comes from decaying plants and animals.
I gave my students this multiple choice question: Mount Arenal, a volcano in Costa Rica, is erupting. Heat is being released during the eruption. What is the source of the heat?

Only one answer is correct among these 4 choices:
- The heat comes from the Sun.
- The heat comes from pools of underground water.
- The heat comes from deep within Earth.
- The heat comes from decaying plants and animals.

Could you tell me which one is correct?

The heat comes from deep within Earth.