While `Fe^(3+)` is stable `Mn^(3+)` is not stable in acitic solution because
A. `O_(2)` oxidises `Mn^(2+)` to `Mn^(3+)`
B. `O_(2)` oxidises both `Mn^(2+)` to `Mn^(3+)` and `Fe^(2+)` to `Fe^(3+)`
C. `Fe^(3+)` oxidises `H_(2)O` to `O_(2)`
D. `Mn^(3+)` oxidise `H_(2)O` to `O_(2)`
