A transition metal (M) among Mn, Cr, Co and Fe has the highest standard electrode potential ( M^3+ / M^2+). It forms a metal complex of the type [ M…

A transition metal (M) among Mn, Cr, Co and Fe has the highest standard electrode potential $\displaystyle \left(\mathrm{M}^{3+} / \mathrm{M}^{2+}\right)$. It forms a metal complex of the type $\displaystyle \left[\mathrm{M}(\mathrm{CN})_6\right]^{4-}$. The number of electrons present in the $\displaystyle \mathrm{e}_{\mathrm{g}}$ orbital of the complex is $\displaystyle \_\_\_\_$.