If ${\mathrm{\Delta }}_0$ is crystal field splitting energy and P is mean pairing energy per pair then stabilizing energy of complex  ${\left[{\mathrm{FeF}}_6\right]}^{4-}$ is :

The stabilizing energy of complex ${\left[{\mathrm{FeF}}_6\right]}^{4-}$ is $-0.4 {\mathrm{\Delta }}_0$.

Where, ${\mathrm{\Delta }}_0$ is crystal field spitting energy and P is mean pairing energy per pair.

Thus, the correct option is D.