what is the source of energy in most ecosystems?\nanimals\nplants\noxygen\nsunlight

Answer:

D. sunlight

Brief Explanations:

In most ecosystems, sunlight is the primary energy source. Through photosynthesis, plants convert solar - energy into chemical energy, which then supports the entire food - web. Animals consume plants or other animals that have consumed plants. Oxygen is a by - product of photosynthesis and is used in respiration, but it is not an energy source.