Which of the following animals lay eggs with protective shells?

fish

amphibians

mollusks

reptiles

Fish lay eggs with a protective cover. Amphibians also lay eggs with protective shells. Reptiles can go either way

If only one option can be chosen; Reptiles. If its more than one then I'd put Reptiles and mollusks.

Explanation:

Reptile eggs are laid out of water and are surrounded by a protective shell, either flexible or inflexible. Mollusks are also known to lay eggs with a hard shell using calcite to construct the eggshells. Fish and amphibians generally lay eggs which are surrounded by the extraembryonic membranes but do not develop a shell, hard or soft, around these membranes. Some fish and amphibian eggs have thick, leathery coats, especially if they must withstand physical force or desiccation.