Which of the following molecular orbital has the lowest energy for O₂ molecule ?

${\mathrm{O}}_2 : \mathrm{\sigma }1{\mathrm{s}}^2\mathrm{\sigma }*1{\mathrm{s}}^2\mathrm{\sigma }2{\mathrm{s}}^2\mathrm{\sigma }*2{\mathrm{s}}^2\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{z}}^2\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}}^2\mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}^2\mathrm{\pi }*2{\mathrm{p}}_{\mathrm{y}}^1\mathrm{\pi }*2{\mathrm{p}}_{\mathrm{x}}^1\mathrm{\sigma }*2{\mathrm{p}}_{\mathrm{z}}^0$

$\mathrm{\sigma }2{\mathrm{p}}_{\mathrm{z}}$ has lower energy than $\mathrm{\pi }2{\mathrm{p}}_{\mathrm{y}} \mathrm{and} \mathrm{\pi }2{\mathrm{p}}_{\mathrm{x}}$ for molecules having more than 14 electrons.