Select the ion having $p\pi -d\pi$ bond :

The ion having $p\pi -d\pi$ bond is ${\mathrm{SO}}_4^{-2}$, ${\mathrm{PO}}_4^{-3}$and ${\mathrm{ClO}}_4^{-}$.

One electron pair is transferred to the matching empty orbital on the other atom in a bond between two atoms when one atom has one vacant orbital and the other atom has one lone pair of electrons. This type of bonding is known as $p\pi -d\pi$ bonding.
${\mathrm{SO}}_4^{-2}$, ${\mathrm{PO}}_4^{-3}$and ${\mathrm{ClO}}_4^{-}$ satisfies the condition of forming the $p\pi -d\pi$ bond.

Hence, the option D is correct.