Ecosystems usually become balanced by natural controls, including natural selection. a balanced ecosystem is one in which the first organism on the food chain must outnumber the subsequent organisms on the food chain. there are an equal number of organisms at all levels of the food chain. the last organism on the food chain must outnumber the first organism on the food chain.

The right answer for the question that is being asked and shown above is that: "the first organism on the food chain must outnumber the subsequent organisms on the food chain." Ecosystems usually become balanced by natural controls, including natural selection. A balanced ecosystem is one in which the first organism on the food chain must outnumber the subsequent organisms on the food chain.