The phylum of $Asterias$ is

Which of the following is a consistent group?

Write the general characteristics of the phylum Echinodermata.

Which of the following is a unique characteristic of the phylum Echinodermata?

Assertion : Ambulacral system plays a major role in locomotion of echinoderm.
Reason : Hydraulic pressure of fluid and contraction of muscle of tube feet make possible movement of echinoderm.

The echinoderms are