Match the following columns and select the correct option:

Column $I$	Column $II$
$(a)$ Pneumotaxic Centre	$(i)$ Alveoli
$(b)$ $O_{2}$ Dissociation curve	$(ii)$ Pons region of brain
$(c)$ Carbonic Anhydrase	$(iii)$ Haemoglobin
$(d)$ Primary site of exchange of gases	$(iv)$ $R.B.C.$

• A
  $(a)-(iv), (b)-(i), (c)-(iii), (d)-(ii)$
• B
  $(a)-(i), (b)-(iii), (c)-(ii), (d)-(iv)$
• C
  $(a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)$
• D
  $(a)-(iii), (b)-(ii), (c)-(iv), (d)-(i)$