Answer:
The correct answer is "Flatworms".
Step-by-step explanation:
Cephalization is known in the animal kingdom as an adaptation at which the nervous and sensory tissues are concentrated in the "head." Flatworms were one of the first organisms to show cephalization in its evolution history. Flatworms have its brain and its sense organs (photosensory and chemosensory cells) and concentrated at the anterior end, which is considered an advanced degree of cephalization.