Select the species in which cation is diamagnetic but anion is paramagnetic.

In ${\mathrm{KO}}_2$ cation is diamagnetic but anion is paramagnetic.
After examining the MO configuration of the oxygen, it is discovered that there isn't a single unpaired electron, demonstrating its diamagnetic nature.
It is evident from the aforementioned configurations that only the oxygen atoms ${\mathrm{KO}}_2$ possess unpaired electrons. As a result, it has a paramagnetic characteristic.