$A$ deuterostomic animal is:

Water vascular system is the characteristic of which group of the following:
$(a)$ Porifera $(b)$ Ctenophora $(c)$ Echinodermata $(d)$ Chordata

$A$ : Echinoderms are the only radially symmetrical animals with true coelom.
$R$ : Echinoderms have secondarily adapted to radial symmetry.

Sea lilies are the members of which class?

Triploblastic,coelomate,complete digestive system and radial symmetry is found in$-$

The calcareous ossicles in echinoderms form the