Explanation:

- Earthworm belongs to the phylum Annelida. This group includes segmented worms. They have bodies divided into ring-like segments and a coelomic cavity.

- Option 1: Annelida

- Earthworms are classic examples of this group.

- Includes other worms like leeches.

- Option 2: Mollusca

- Includes animals like snails, clams, and squids.

- They have soft bodies, often with shells.

- Option 3: Arthropoda

- This group contains insects, spiders, and crustaceans.

- They have exoskeletons and jointed appendages.

- Option 4: Nematoda

- Known as roundworms.

- They have simple, unsegmented, cylindrical bodies.