When any plane passing through the central axis of the body divides the organism into two identical halves, the organism is called ___________.

Correct Answer : A.

Radial symmetry is found in coelenterates, ctenophores and echinoderms. The right and left, or the dorsal and ventral sides, in such symmetry are not differentiated. This type of symmetry is advantageous to sessile (attached) animals as they can feed from all directions.