During the change of ${\mathrm{O}}_2$ to ${\mathrm{O}}_2^{-}$, the incoming electron goes to the orbital

The electronic configuration of ${\mathrm{O}}_2$ is
$\left[\mathrm{\sigma }\right(1 \mathrm{s}\left){]}^2\right[\mathrm{\sigma }*(1 \mathrm{s}){]}^2\left[\mathrm{\sigma }\right(2 \mathrm{s}\left){]}^2\right[\mathrm{\sigma }*(2 \mathrm{s}){]}^2\left[\mathrm{\sigma }\right(2\mathrm{pz}\left){]}^2\right[\mathrm{\pi }\left(2{\mathrm{p}}_{\mathrm{x}}\right){]}^2\left[\mathrm{\pi }\right(2{\mathrm{p}}_{\mathrm{y}}\left){]}^2\right[\mathrm{\pi }*\left(2{\mathrm{p}}_{\mathrm{x}}\right){]}^1[\mathrm{\pi }*(2{\mathrm{p}}_{\mathrm{y}}){]}^1$
By accepting one electron ${\mathrm{O}}_2$is converted to ${\mathrm{O}}_2^{-}$
The electronic configuration of ${{\mathrm{O}}_2}^{-}$ is
$\left[\mathrm{\sigma }\right(1 \mathrm{s}\left){]}^2\right[\mathrm{\sigma }*(1 \mathrm{s}){]}^2\left[\mathrm{\sigma }\right(2 \mathrm{s}\left){]}^2\right[\mathrm{\sigma }*(2 \mathrm{s}){]}^2\left[\mathrm{\sigma }\right(2{\mathrm{p}}_{\mathrm{z}}\left){]}^2\right[\mathrm{\pi }\left(2{\mathrm{p}}_{\mathrm{x}}\right){]}^2\left[\mathrm{\pi }\right(2{\mathrm{p}}_{\mathrm{y}}\left){]}^2\right[\mathrm{\pi }*\left(2{\mathrm{p}}_{\mathrm{x}}\right){]}^2[\mathrm{\pi }*(2{\mathrm{p}}_{\mathrm{y}}){]}^1$
The incoming electron of ${{\mathrm{O}}_2}^{-}$ will be enter into the $[\pi *(2\mathrm{px}\left)\right]$ orbital.

Hence, the correct option is (A)