The correct option is C Reducing in (a) and (b)
In the reaction,
(a) H2O2+0O3⟶H2O+2O2
Since, H2O2 reduces O3 into O2− ion, thus it behaves as a reducing agent. Further, in the reaction,
(b) H2O2+Ag2O⟶2Ag+H2O+O2
Here, H2O2 reduces Ag2O into metallic silver [Ag] (as oxidation number is reducing from +1 to 0). Thus, H2O2behaves as a reducing agent.
Hence, option (c) is correct.