Question

phylum echinodermata
holothuroidea (sea cucumbers): sea cucumbers have long, cylindrical bodies with leathery skin and tentacle-like structures surrounding their mouth.
these classes encompass a diverse range of echinoderm species, each with its own unique characteristics and adaptations.
which echinodermata class is composed of sea cucumbers?
holothuroidea
echinoidea
ophiuroidea

Explanation:

The text in the image states "Holothuroidea (Sea Cucumbers): Sea cucumbers have long, cylindrical bodies...", which directly indicates that the class Holothuroidea is composed of sea cucumbers.

Answer:

A. Holothuroidea