Echinoderms are descended from bilaterians, but many members of the group lack a brain, have no specialized sense organs, and have radial nerves that extend down each "arm" from a central nerve ring that surrounds the gut. What was a likely selective pressure in the evolution of this type of nervous system?
A)ability to move forward B)role as a predator in the ecosystem C)multicellularity D)possession of an endoskeleton of calcium carbonate E)None of the other answer options is correct.