Why are food chains relatively short? A) Top-level feeders tend to be more numerous than lower-trophic-level species. B) Top-level feeders tend to be small but are capable of conserving more energy. C) Longer chains are less stable and energy transfer between levels is inefficient. D) There are only so many organisms that are adapted to feed on other types of organisms. E) Food chain length is ultimately determined by the photosynthetic efficiency of producers.