Match List-I with List-II and choose the correct answer from the options given below.

List - I	List - II
(a) Metamerism	(i) Coelenterata
(b) Canal system	(ii) Ctenophora
(c) Comb plates	(iii) Annelida
(d) Cnidoblasts	(iv) Porifera

To solve the matching question we compare each term in List‑I with the groups in List‑II and identify the characteristic that uniquely belongs to each phylum.

(a) Metamerism refers to the presence of repeated body segments. This feature is a hallmark of segmented worms, which belong to the phylum Annelida. Therefore, a matches with (iii) Annelida.

(b) Canal system describes a network of water‑filled canals that filter water through a porous body. Such a system is typical of sponges, which are classified under the phylum Porifera. Hence, b matches with (iv) Porifera.

(c) Comb plates are rows of ciliary plates used for locomotion in “comb jellies.” These structures are unique to the phylum Ctenophora. Consequently, c matches with (ii) Ctenophora.

(d) Cnidoblasts are specialized stinging cells (nematocysts) found in cnidarians, a group also called Coelenterata. Thus, d matches with (i) Coelenterata.

Putting all the matches together gives the final answer: a – iii, b – iv, c – ii, d – i.