Which of the following is paramagnetic?

The total number of electrons in all bonding molecular orbitals of $O_{2}^{2-}$ is $....$ (Round off to the Nearest Integer).

Provide the energy level diagram of the molecular orbital obtained by the overlapping of $2p_x^1$ orbitals of two atoms.

Four diatomic species are listed below. Identify the correct order in which the bond order is increasing in them.

What is the bond order of $B_{2}$ molecule?

According to Molecular Orbital Theory,which of the following statements is/are correct?
$(A)$ $C_2^{2-}$ is expected to be diamagnetic
$(B)$ $O_2^{2+}$ is expected to have a longer bond length than $O_2$
$(C)$ $N_2^{+}$ and $N_2^{-}$ have the same bond order
$(D)$ $He_2^{+}$ has the same energy as two isolated $He$ atoms