Select the molecule in which hybridization of phosphorus is ${\mathrm{sp}}^3$.

Phosphoric acid has the chemical formula ${\mathrm{H}}_3{\mathrm{PO}}_4$, where the hybridization of the phosphorus atom is ${\mathrm{sp}}^3$. Three hydroxyl groups surround the phosphorus atom, which is doubly linked to the oxygen atom. As a result, all of the electrons are involved in the hybridization process, which results in ${\mathrm{sp}}^3$ hybridization.

Thus, molecule in which hybridization of phosphorus is ${\mathrm{sp}}^3$ are,

${\mathrm{H}}_3{\mathrm{PO}}_4$, ${\mathrm{P}}_4{\mathrm{O}}_6$ and ${\mathrm{P}}_4{\mathrm{O}}_{10}$.