Echinoderms lack a centralized nervous system.
All echinoderms are deuterostomes .
Some deuterostomes lack a centralized nervous system.
Some deuterostomes lack a centralized what?
Options:
(a) DNA
(b) eardrum
(c) critical organs
(d) permineralization
(e) A ruler
(f) nervous system
(g) communication center
(h) respiratory system