What is common between the trichocysts of $Paramecium$ and the nematocysts of $Hydra$?

Match the animals listed under Column-$I$ with their respective zoological names given under Column-$II$; choose the answer that provides the correct combination of the alphabets of the two columns.
Column-$I$ (Common Name) | Column-$II$ (Zoological Name)
$A$. Starfish | $p$. Sepia
$B$. Jellyfish | $q$. Astropecten
$C$. Devilfish | $r$. Aurelia
$D$. Cuttlefish | $s$. Octopus

Match the following columns regarding the number of heart chambers in different animals:

Column-$I$	Column-$II$
$(a)$ Two-chambered	$(i)$ Peacock
$(b)$ Three-chambered	$(ii)$ Labeo
$(c)$ Incomplete four-chambered	$(iii)$ Ichthyophis
$(d)$ Four-chambered	$(iv)$ Lizard

Which group of animals consists of poikilothermic (cold-blooded) animals?

Which of the following is the correct matching of an animal,its characteristics,and its taxon?

Which of the following is correctly matched?