The total number of unpaired electrons present in the complex ${\mathrm{K}}_3\left[\mathrm{Cr}(\text{ oxalate }{)}_3\right]$ is

In this complex Cr present in +3 oxidation state hence have it has outer electronic configuration is${\mathrm{t}}_{2\mathrm{g}}^3{\mathrm{e}}_{\mathrm{g}}^0$.There will be no pairing due to weak field ligand is present hence there is 3 unpaired electrons.

Hence, correct answer is 3.