The correct option is A E=M6
The oxidation number of Cr in K2Cr2O7 is +6.
The oxidation number of Cr in Cr2(SO4)3 is +3.
Thus, the oxidation number of Cr changes by 3.
Total change in the oxidation number of two Cr atoms is 6.
Equivalent weight=Molecular weightChange in the oxidation number
Hence, E=M6