Which of the following sets of animals belongs to the same phylum?

Which of the following statements are true/false?
$(i)$ In $Torpedo$,the electric organs are capable of generating strong electric shock to paralyze the prey.
$(ii)$ Bony fishes use pectoral,pelvic,dorsal,anal,and caudal fins in swimming.
$(iii)$ Amphibian skin is moist and has thick scales.
$(iv)$ Birds are poikilothermic animals.
$(v)$ The most unique mammalian characteristic is the presence of milk-producing mammary glands by which the young ones are nourished.

Give the correct match in the following:

Column-$I$	Column-$II$
$(A)$ Flame Cells	$(p)$ Sponges
$(B)$ Collar Cells	$(q)$ Hydra
$(C)$ Stinging cells	$(r)$ Planaria
	$(s)$ Ascaris

Which one of the following occurs in molluscs but not in echinoderms?

Which of the following is considered a living fossil?

Choose the incorrect statement.