Echinoderms have a unique water vascular system with tube feet.
Each starfish arm is lined with tube feet.
Starfish are echinoderms.
What phylum do starfish belong to?
Options:
a: fertile
b: animals
c: Echinoderm.
d: Mollusca.
e: Sponge.
f: Absorb light
g: Annelid.
h: a fish