$\sigma _{2s}^*$ orbital is similar to ....... orbital

During the change of $O _{2}$ to $O _{2}^{-}$, the incoming electron goes to the orbital :

Bond order of $1.5$ is shown by-

Correct decreasing order of bond order of oxygen species in $I$ to $IV$

$(I)$   $Na_2O_2$

$(II)$  $O_2 [AsF_6]$

$(III)$  $CsO_2$

$(IV)$  $O_2$

Which of the following options represents the correct bond order?

Which of the following is paramagnetic ?