In phylum Echinodermata, the adult echinoderms are _____A_____ but larvae are _____B____.

Echinoderms are a phylum of marine animals. The adults are recognizable by their (usually five-point) radial symmetry, whereas the larvae are bilaterally symmetrical. For example starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies".