radiation conduction convection insulation
I gave my students this multiple choice question: A dark colored wall becomes warm when the Sun is shining on it. After the Sun sets, a person standing a meter away can feel warmth from the wall. How does heat transfer from the wall to the person?

Only one answer is correct among these 4 choices:
- radiation
- conduction
- convection
- insulation

Could you tell me which one is correct?

radiation