The answer is B. Shark. This is because sharks are a "sea" creature. So they will only be found in the ocean OR in a salt-water aquarium.
i think it would be the shark option. there is one kind of shark that can live in any water and that is the bull shark. it can live in a lake, freshwater ocean and many more. researchers put other shark species into freshwater and noticed that they move slower in freshwater.
hope i helped