Which of the following is diamagnetic?

Diamagnetic species have all electrons paired, whereas paramagnetic species have unpaired electrons. $\mathrm{H}_2=\sigma 1 \mathrm{~s}^2$ No. of unpaired electron $=0 \Rightarrow$ diamagnetic $\mathrm{H}_2^{-}=\sigma 1 s, \sigma^* 1 s^1$ No. of unpaired electron $=1 \Rightarrow$ paramagnetic $\mathrm{H}_2^{-}=\sigma 1 s^1$ No. of unpaired electron $=1 \Rightarrow$ paramagnetic $\mathrm{He}_2^{+}=\sigma 1 s^2, \sigma^* 1 s^1$ No. of unpaired electron $=1 \Rightarrow$ paramagnetic