While comparing invertebrate groups, a phylogeny lecture uses sea stars to explain invertebrate links with vertebrate ancestry. The feature being tested is:

Echinoderms are deuterostomes, like chordates. Although adult echinoderms look very different, embryological traits connect them more closely to chordates than to protostomes such as arthropods. This MCQ belongs to the Comparative zoology topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.