Which of the following are arranged in an increasing order of their bond strengths ?

Question

$\begin{array}{1 1} a)O_2^{-} < O_2 < O_2^{+} < O_2^{2-} \\ b) O_2^{2-} < O_2^{-} < O_2 < O_2^{+} \\ c)O_2^{-} < O_2^{2-} < O_2 < O_2^{+} \\ d)O_2^{+} < O_2 < O_2^{-} < O_2^{2-} \end{array} $