Match the following columns:

Column-$I$	Column-$II$
$(a)$ Amphibia	$(1)$ Air bladder
$(b)$ Mammalia	$(2)$ Cartilaginous notochord
$(c)$ Chondrichthyes	$(3)$ Mammary gland
$(d)$ Osteichthyes	$(4)$ Pneumatic bones
$(e)$ Cyclostomata	$(5)$ Dual habitat
$(f)$ Aves	$(6)$ Jawless,circular,sucking mouth

(A) The correct matching is: $(a-5, b-3, c-2, d-1, e-6, f-4)$.
$(a)$ Amphibia - Dual habitat: They are adapted to live on both land and water.
$(b)$ Mammalia - Mammary gland: They possess milk-producing glands to nourish their young ones.
$(c)$ Chondrichthyes - Cartilaginous notochord: They have a persistent cartilaginous endoskeleton.
$(d)$ Osteichthyes - Air bladder: They possess an air bladder which regulates buoyancy.
$(e)$ Cyclostomata - Jawless,circular,sucking mouth: They have a circular mouth without jaws,used for suction.
$(f)$ Aves - Pneumatic bones: They have hollow,air-filled bones that reduce body weight for flight.