Which of the following is elaboration?

1: The adaptations that allow deep sea creatures to survive in extreme
environments are awareness of predators, adjusting to the environment, and the
ability to get food.
2: This means that when squids are alerted of their enemies, they first camouflage
themselves. If that plan does not work well, they squirt ink to get away from their
predators.
3: According to another article on zombie worms, "the skin cells of these structures
produce an acid, that dissolve the whale's bone, allowing the worm to extract the
nutrients" ("Deep Sea Vents").
4: Without adaptations like these, many deep-sea creatures would have become
extinct.