Choose the incorrect statement (s )-
A. 1 mole of `MnO_(4)^(-)` ion can oxidize 10 moles of `Fe^(2+)` ion in acidic medium
B. 1 mole of `Cr_(2)O_(7)^(2-)` ion can oxidize 12 moles of `Fe^ (2+)` ion in acidic medium
C. 2 mole of `Cu_(2)S` can be oxidized by 2.6 moles of `MnO_(4)^(-)` ion in acidic medium `(Cu_(2)StoCu^(2+)SO_(2))`
D. 7.5 mole of `Cu_(2)S` can be oxidized by 10 moles of `Cr_(2)O_(7)^(2-)` ion in acidic medium `(Cu_(2)StoCu^(2+)SO_(2))`