Q: Fact 1: Most invertebrates have a nervous system. Fact 2: Invertebrates are animals without a backbone. Given the two facts above, which type of system do most animals without backbones have?

Pick your answer from: (I) sensory neurons; (II) Veins and arteries.; (III) Nervous system; (IV) Stereo system; (V) Root system; (VI) to move people; (VII) Skeletal system; (VIII) insects;
A:
(III)