`E_(Mn^(3+)//Mn^(2+))^@`is highly positive than that of `E_(Cr^(3+)//Cr^(2+))^@orE_(Fe^(3+)//Fe^(2+))^@` because

Options

A. `Mn^(2+)(d^5)` can be easily oxidised to `Mn^(3+)(d^4)` due to low ionisation enthalpy
B. third ionisation enthalpy of Mn is much larger due to stable half filled `d^5` electronic configuration of `Mn^(2+)`
C. `Mn^(3+)` is more stable than `Mn^(2+)` due to higher oxidation state
D. second ioonisation enthalpy of Mn is higher than third ionisation enthalpy.

Answer

B