Dan outfitted his house to run on the oldest heat source on Earth. What is the oldest heat source on Earth?\nOptions:\n- fire\n- solar energy\n- sun\n- house\n- coal or wood Let's think step by step:
User
Solar energy is the energy that is collected from the heat of sunlight. Sun is the centre of the galaxy in which earth is present. Sun is older than the earth. So, the answer is solar energy.
Assistant