Which of the following possess larval stages?

Match the following columns and select the correct option.

Column-$I$	Column-$II$
$(a.)$ Sea fan	$(i)$ Mandarina
$(b.)$ Sea hare	$(ii)$ Taenia
$(c.)$ Radial symmetry	$(iii)$ Gorgonia
$(d.)$ Endoparasite	$(iv)$ Aplysia

Give one example each for an animal possessing placoid scales and that with cycloid scales.

Match the following columns:

Column-$I$	Column-$II$
$(a)$ Barbus	$(i)$ Epidermal scales
$(b)$ Crocodile	$(ii)$ Absence of head
$(c)$ Amphioxus	$(iii)$ Cycloid scales
$(d)$ Lamprey	$(iv)$ Scaleless skin

Identify the correctly matched pair.

Provide the appropriate technical term for the following descriptions:
$(a)$ Blood-filled cavity in arthropods.
$(b)$ Free-floating form of cnidaria.
$(c)$ Stinging organ of jellyfish.
$(d)$ Lateral appendages in aquatic annelids.