It is the remains of ancient animals and plants that make up fossil fuels Fossil fuels are non-renewable<span> because they will run out one day Wood can be used for fuel and is </span>renewable<span> if trees are replanted. </span>Biomass<span> which is material from living things can be </span>renewable<span> if plants are replanted.</span>
I think it is c because of organs would be classified as an organ system<span />