Answer: C) The species eat different foods.
Explanation: The passage mentions that the finches varied mainly in the size and shape of their beaks, which is directly related to their diet. The different species of finches have adapted to different food sources available on the Galapagos Islands. For example, some species eat seeds from the ground, others eat seeds from cactuses, and some eat insects from trees. These variations in diet and feeding habits have led to the evolution of different finch species.