Answer: A. Solar energy
Step-by-step explanation:
The sun is the primary source of energy that guarantees the existence of life in the land. The source of solar energy is nuclear fusion reactions between hydrogen nuclei, resulting in helium nuclei and a certain amount of energy. This energy is radiated by the sun in the form of electromagnetic radiation with a power distribution that covers virtually every region of the electromagnetic spectrum, but that has its maximum intensity in the region that goes from ultraviolet to infrared.
The energy of the sun that reaches the earth (about 1.7 x 1017 J.s-1) is captured by plants, photosynthetic bacteria (cyanobacteria) and by the ocean. The part absorbed by plants corresponds, approximately 0.025% of the total solar energy that arrives at the surface of the earth. In this way, the energy produced by nuclear fusion within the Sun and carried to Earth in the form of electromagnetic radiation (photons) is transformed into chemical energy and stored in the form of chemical bonds in plant molecules.
Animals feed on plants to acquire some of the energy stored in the molecules of plants to make their molecules and keep their cells working. Animals use the energy acquired by the moving food, breathing, temperature control keeps your organs and immune system functioning, grow, reproduce, etc.