Answer:
Option D, Echinoderm
Explanation:
Deuterostome are species which are bilalteral in structure and the first embryonic opening becomes the anus.
There are three classes of deuterostome namely
• Chordata
• Echinodermata
• Hemichordata
The sea urchin belongs to the phylum Echinodermata which have radial symmetry (includes starfish etc.) and have a unique a water-vascular system (hydraulic system) which is used for respiration, locomotion and transportation of food item.
Thus, option D is the correct answer.
