Which statement is not true about invertebrate animals?
a) most animal phyla are invertebrates.
b) all major invertebrate groups arose from protistan ancestors.
c) the vast majority of animal species are invertebrates.
d) many invertebrate species live in a marine environment.
e) invertebrates lack a nervous system.

e) Invertebrates lack a nervous system

Explanation:

One of the main characteristics of invertebrates is that they don't have a backbone. Backbones belong to the skeletal system. A totally different story is the nervous system which runs inside the backbone. Although the more complex nervous systems appear in vertebrates the simply fact of having eyes like crabs or insects implies having a nervous system that can control them.