* Segmentation refers to the division of an animal's body into repeating units, like segments or sections. This allows for specialization of different body parts.

* Human beings (A), earthworms (B), and insects (C) all exhibit segmentation. Humans have a segmented vertebral column, earthworms have obvious external segments, and insects have body segments like the head, thorax, and abdomen.

* Jellyfish (D) are radially symmetrical animals, meaning their bodies are organized around a central axis. They lack the distinct, repeated segments found in segmented animals.