Which of the following is the ultimate source of energy?
Sun
The sun is the ultimate source of energy. Photosynthesis is driven by solar energy, which create food for plants. Humans and animals also depend on sun for various purposes.
The water cycle is also maintained because of the solar energy which causes the water to convert into water vapour.
Energy sources like coal, oil, petroleum etc. are created over very long periods of time from decayed and fossilized living matter (animals and plants), and the energy in that living matter originally came from the sun.