Sea anemone belongs to which class?

Write the characteristics of Phylum Coelenterata (Cnidaria).

Which of the following cells are present only in the epidermis of Hydra?
$(A)$ Interstitial cells
$(B)$ Cnidoblasts
$(C)$ Sensory cells
$(D)$ Germ cells

In the ectoderm of $Hydra$,the bulk of cells are:

Among the following organisms, identify the completely non-parasitic form.

Which type of larva is found in the phylum $Cnidaria$?