Which one of the following species doesn't have a magnetic moment...

Species must not contain single unpaired

${O}_{2}^{+} \to {\sigma}_{1s}^{2} < {\sigma}_{1s}^{* 2} < {\sigma}_{2s}^{2} < {\sigma}_{2s}^{* 2} < {\sigma}_{2pz}^{2} < {\pi}_{2px}^{2} = {\pi}_{2py}^{2} < {\pi}_{2px}^{* 1} = {\pi}_{2py}^{* 0}$

unpaired ${e}^{-} = 1 ∴ \mu = 1 . 73BM$

(1) ${Cu}^{+}{I}^{-}{Cu}^{+} \to [ Ar ] 3{d}^{10} ∴$ unpaired ${e}^{-} = 0$

${I}^{-} \to [ Xe ] ∴$ unpaired ${e}^{-} = 0$

therefore $\mu = 0$

$3 . \left[Cu{\left({NH}_{3}\right)}_{4}\right]{Cl}_{2}$

$Cu \to [ A ] 3{d}^{3} ∴$ unpaired $= 1 ∴ \mu = 1 . 73BM$

$4 . {O}_{2}^{-} \to d$

${\sigma}_{1s}^{2} < {\sigma}_{1s}^{{*}_{2}} < {\sigma}_{2s}^{2} < {\sigma}_{2s}^{* 2} < {\sigma}_{2pz}^{2} < {\pi}_{2px}^{2} = {\pi}_{2py}^{2} < {\pi}_{2px}^{* 2} = {\pi}_{2py}^{* 1}$

1 Unpaired electron

$∴$ unpaired $∴ \mu = 1 . 73BM$