A.KMnO4 B.1/2KMnO4 C.1/4KMnO4 D.1/5KMnO4
A.1/2K2Cr2O7 B.1/3K2Cr2O7 C.1/6K2Cr2O7 D.K2Cr2O7
A.12.5 B.25 C.50 D.6