The maximum number of $90^{\circ}$ angles between bond pair of electrons is observed in

Question

$\begin{array}{1 1} a) \;dsp^3\;hybridization \\ b) \;sp^3d^2\;hybridization\\ c) \;dsp^2\;hybridization \\ d)\;sp^3d\;hybridization \end{array} $