10) which of the following is an example of an ecosystem? a) all of the brook trout in a 500 hectare2 river drainage system. b) the plants, animals, and decomposers that inhabit an alpine meadow. c) a pond and all of the plant and animal species that live in it. d) the intricate interactions of the various plant and animal species on a savanna during a drought. e) interactions between all of the organisms and their physical environment in a tropical rain forest.