If z-axis is taken as the molecular axis, then $\mathrm{\pi }$ orbital are formed by

If the z axis is molecular axis, then $\mathrm{\pi }$ - molecular orbitals are formed by the overlap of ${\mathrm{p}}_{\mathrm{x}}+{\mathrm{p}}_{\mathrm{x}}$. It is formed by orbitals in the perpendicular plane to Z-axis

Hence, the correct option is option (B) $2{\mathrm{p}}_{\mathrm{x}}\text{ and }2{\mathrm{p}}_{\mathrm{x}}$.