How many of the following compounds have ${\mathrm{sp}}^3$ hybridization?
a) ${\mathrm{SO}}_4^{-2}\text{ (b) }{\mathrm{SO}}_5^{-2}\left(\mathrm{c}\right){\mathrm{PO}}_4^{-3}$ d)${\mathrm{PO}}_5^{-3}\left(\mathrm{e}\right){\mathrm{I}}_3^{-}\left(\mathrm{f}\right){\mathrm{CO}}_3^{-2}\left(\mathrm{g}\right){\mathrm{CO}}_4^{-2}$

The acids, per acids and their ions have same hybridization of central atom Thus, ${\mathrm{SO}}_4^{-2},{\mathrm{SO}}_5^{-2},{\mathrm{PO}}_4^{-3},{\mathrm{PO}}_5^{-3}$all have same  ${\mathrm{SP}}^3$ hybridization ${\mathrm{I}}_3^{-}$ have  ${\mathrm{SP}}^3\mathrm{d}$ hybridization  ${\mathrm{CO}}_3^{-2},{\mathrm{CO}}_4^{-2}$ have ${\text{SP}}^2$ hybridisation