Hi,
your answer to this response will be :Anthozoa
Phylum Cnidaria includes such diverse forms as jellyfish, hydra, sea anemones, and corals. Cnidarians are radially or biradially symmetric, a general type of symmetry believed primitive for eumetazoans. They have achieved the tissue level of organization, in which some similar cells are associated into groups or aggregations called tissues, but true organs do not occur. Cnidarian bodies have two or sometimes three layers. A gastrovascular cavity (coelenteron) has a single exterior opening that serves as both mouth and anus. Often tentacles surround the opening. Some cells are organized into two simple nerve nets, one epidermal and the other gastronomical, that help coordinate muscular and sensory functions.
Cnidarians have two basic body forms, medusa and polyp. Medusae, such as adult jellyfish, are free-swimming or floating. They usually have umbrella-shaped bodies and tetrameters (four-part) symmetry. The mouth is usually on the concave side, and the tentacles originate on the rim of the umbrella.