Which of the following would have same magnetic nature whether $\mathrm{sp}$ mixing is operative or not?

${\mathrm{O}}_2$ have same magnetic nature whether $\mathrm{sp}$ mixing is operative or not,
When the energies of the s and p orbitals are comparable, s-p mixing takes place. As a result, the 2p orbitals for O have a greater energy than those for B and C. Because of this, ${\mathrm{B}}_2$ and ${\mathrm{C}}_2$ do have s-p mixing but ${\mathrm{O}}_2$ has very little (insufficient to modify the energy ordering).