In a well balanced ecosystem, squirrels eat nuts, raccoon feed on squirrels, and bears feed on raccoons. It was observed that they were more squirrels and fewer raccoons. This situation indicates that

What is a food chain? a.different animals located in different communities b. energy transferred from the sun to plants and then to a series of living things c. rows of crops, such as lettuce, in a field d.animals using one another as food for energy and growth