Correct Answer: D
Explanation:
D. Salamanders (along with frogs and snake-like caecilians) are tetrapods that lack watertight, amniotic eggs. Amphibians must lay their eggs in moist environments. Sharks are not tetrapods, and ostriches, rattlesnakes, and kangaroos are all amniotes. (Note that mammals are considered amniotes because they evolved from an ancestor with an amniotic egg.)