${\mathrm{N}}_2$ and ${\mathrm{O}}_2$ are converted into mono anions ${\mathrm{N}}_2^{-}$ and ${\mathrm{O}}_2^{-}$ respectively, which of the following statements is wrong ?

${\mathrm{O}}_2$ has two unpaired electrons in its ${\mathrm{\sigma \pi }}^{*}$molecular orbitals, one electron goes to ${\pi }^{*}$ orbital
to form ${\mathrm{O}}_2^{-}$
Bond order in oxygen molecule $\left({\mathrm{O}}_2^{-}\right)$
=0.5 [(Number of bonding electrons) - (number of anti-bonding electrons)]
=0.5[10-7]
=1.5
Therefore, bond order of ${\mathrm{O}}_2^{-}$ decreases.
In the same way one electron goes to ${\pi }^{*}$ orbital to form ${\mathrm{N}}_2^{-}$ and bond order decreases and it also become para magnetic.
Hence, correct answer is B. In ${\mathrm{O}}_2^{-} , \mathrm{O}-\mathrm{O}$ bond order increases