Match each species in List-I with the hybridisation of its central atom in List-II. Count every region of electron density on the central atom: a bonded atom counts as one region, whatever the bond order, and so does a lone pair. List-I (Species) A. $\text{NO}_2^+$ B. $\text{CO}_3^{2-}$ C. $\text{SO}_4^{2-}$ D. $\text{SF}_4$ List-II (Hybridisation of the central atom) I. $sp^3$ II. $sp$ III. $sp^3d$ IV. $sp^2$