Answer the following question given this paragraph: 

Cnidarians are invertebrates such as jellyfish and corals. They belong to Phylum Cnidaria. All cnidarians are aquatic. Most of them live in the ocean. Cnidarians are a little more complex than sponges. Besides specialized cells, they have tissues and radial symmetry. There are more than 10,000 cnidarian species, see Figure below .


Q: What type of invertebrates are jellyfish and corals known as?

 Choices:

- sponges

- nautilus

- cephalopods

- cnidarians

A:
cnidarians
