Answer:
Annelid
Step-by-step explanation:
"Leech belong to phylum Annelida because they have metamerically segmented body."
Another definition example:
Annelids also known as the ringed worms or segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches.
Leeches are segmented parasitic or predatory worms that comprise the subclass Hirudinea within the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular segmented bodies that can lengthen and contract.
Leeches are classified as this because they are segmented and have soft bodies similar to worms which are also considered annelids.