Which of the following animals does not belong to the phylum $Mollusca$?

Match the following columns:

Column-$I$	Column-$II$
$I$. Choanocytes	$p$. Cnidaria
$II$. Cnidoblasts	$q$. Platyhelminthes
$III$. Flame cells	$r$. Porifera
	$s$. Aschelminthes

Match the following columns and select the correct option.
Column $-I$ | Column $-II$
$(a)$ $6-15$ pairs of gill slits | $(i)$ Trygon
$(b)$ Heterocercal caudal fin | $(ii)$ Cyclostomes
$(c)$ Air Bladder | $(iii)$ Chondrichthyes
$(d)$ Poison sting | $(iv)$ Osteichthyes

Identify the correct terms for the following analogy-based questions:
$(i)$ Aquatic Annelids : Parapodia :: Arthropods : ....
$(ii)$ Annelids : Nephridia :: Arthropods : ....

Identify the mismatched pair.

Match the items in Column-$I$ with Column-$II$ and select the correct option:

Column-$I$	Column-$II$
$(A)$ Fish	$(i)$ Two atria and one ventricle
$(B)$ Frog	$(ii)$ One atrium and one ventricle
$(C)$ Snake	$(iii)$ Two atria and two ventricles
$(D)$ Ostrich	$(iv)$ Two atria and incompletely divided ventricle