${\mathrm{p}}_{\mathrm{y}}\text{-orbital can not form }\mathrm{\pi }\text{-bond by lateral overlap with : }$

$\text{ (i) }{\mathrm{d}}_{\mathrm{xz}}\text{ orbital }$      $\text{ (ii) }{\mathrm{d}}_{{\mathrm{x}}^2-{\mathrm{y}}^2}\text{ orbital }$        $\text{ (iii) }{\mathrm{d}}_{\mathrm{xy}}\text{ orbital }$            $\text{ (iv) }{p}_z\text{ orbital }$

The d_xz and d_xy orbitals have lobes oriented in planes suitable for side-on overlap (lateral) with p orbitals, facilitating π-bond formation.

The p_z orbital is itself a p orbital capable of π bonding with other p or compatible d orbitals.

However, the d_x²−y² orbital has its lobes oriented directly along the x and y axes, making its symmetry incompatible for lateral overlap with p orbitals, which typically limits π-bond formation.

Therefore, the correct option is: (ii) d_x²−y² orbital.