The skulls and pelvic bones of some species of dinosaur share characteristics with the skulls and pelvic bones of all modern birds. Even though not all dinosaurs have these characteristics, there are scientists who claim that all animals that do have these characteristics are dinosaurs. If the statements above and the claim of the scientists are true, which of the following must also be true? ['All dinosaurs are birds.', 'Birds share more characteristics with dinosaurs than they do with other animals.', 'All animals whose skulls share the characteristics of those of modem birds also have pelvic bones that are similar to those of modern birds.', 'Modern birds are dinosaurs.']