The bond length in the species $O_2,O_2^+$ and $O_2^-$ are in the order

Question

$\begin{array}{1 1}(a)\;O_2^+ > O_2 > O_2^-\\ (b)\;O_2^+ > O_2^- > O_2 \\(c)\;O_2 > O_2^+ > O_2^-\\(d)\;O_2^- > O_2 > O_2^+\end{array} $