8) Base your answer on the information below and on your knowledge of biology. Unique populations of giant tortoises live in the Galapagos Islands. This is the same group of islands where Darwin studied his famous finches. It is thought that the original ancestors of today's giant tortoises came from the mainland of South America. These animals left and drifted in the ocean to the islands where they began to live, reproduce, and evolve. Each of the islands has a different habitat. Each species varies in shell shape and body structure. Information about two of these species of giant tortoises and their habitats is found in the table below. Which statement best explains the differences observed in the tortoises on each island? A) Each tortoise adapted to its environment during its lifetime. B) Sudden mutations changed the appearance of all of the tortoises. C) The tortoises grew different structures based on the available food. D) Different adaptations gave some tortoises a better chance of survival.