Answer: D: availability of water
Explanation: In an ecosystem, water can affect how the organisms can survive because organisms caanot survive without water.
An ecosystem refers to the set of species in a given area that interact with one another and also with their non-living environments such as earth, weather, sun, soil, climate and so on. These species including plants, animals, bacteria and fungi, depend on each other. It relates to how all these different organisms live in closeness with each other and interact with another.