Deuterostome is any member of the phylum Echinodermata, Hemichordata, and Chordata in which anus appears first, developing at or near the blastopore, cleavage is radial and indeterminate, and mesoderm and coelom arise from the primitive gut. so. the ans is (c)

Members of the group Arthropods are not deuterostomes.

Deuterostomes are a superphylum of animals that exhibit a specific pattern of embryonic development known as deuterostomy. In deuterostomes, the blastopore (the opening of the developing embryo) eventually forms the anus, while the mouth is formed from a secondary opening. This pattern is distinct from protostomes, where the blastopore becomes the mouth.

Arthropods, on the other hand, are a large phylum of invertebrate animals that include insects, spiders, crustaceans, and other related organisms. They belong to the group known as protostomes. In protostomes, the blastopore becomes the mouth during embryonic development.

Therefore, the correct answer is option 'C' - Arthropods. Arthropods are not deuterostomes.

- Deuterostomes:
Deuterostomes include chordates (such as humans), echinoderms (such as starfish), and a few other minor groups.
- Arthropods:
Arthropods are a diverse group of invertebrates, including insects, spiders, crustaceans, and others.
- Chordates:
Chordates are a group of animals that possess a notochord (a flexible rod-like structure), a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some point in their life cycle. They include vertebrates (animals with a backbone) and some invertebrate groups (such as lancelets and tunicates).
- Echinoderms:
Echinoderms are a group of marine animals that include starfish, sea urchins, and sea cucumbers. They exhibit radial symmetry and possess a unique water vascular system.

In summary, while chordates, echinoderms, and arthropods are all major groups of animals, only arthropods do not belong to the deuterostomes.