Which of the following phyla is a deuterostome?

A) Annelids
B) Mollusks
C) Flatworms
D) Arthropods
E) Echinoderms

Deuterostome

A classification of animals defined by their developmental characteristics, where the anus forms before the mouth during embryonic development.

Echinoderms

Echinoderms are a group of marine invertebrates that include sea stars, sea urchins, and sand dollars, characterized by radial symmetry and a unique water vascular system.