Not sure about this one but probably. I might be wrong because I often get confused in such questions. But i hope my answer is helpful.
CH4 will be the reducing agent because it is oxidizing it self by oxidizing the carbon and oxidizing the hydrogen while reducing the Oxygen.Â
in CH4 Carbon has the valency -4 and H has +1. in CO2 Carbon has the valency of +4 and Hydrogen in H2O has the valency of +2Â
in C: -4 to +4 is oxidation
in H: +1 to +2 is also oxidationÂ
in O: -2 to to -4 is reduction ( in CO2)Â
concluding CH4 will be the reducing agent and O2 will be the oxidizing agent.Â
Always keep this key in mind: OIL RIG
OIL= Oxidation Is LoosingÂ
RIG= Reduction is GainingÂ
Oxidizing agents always reduce them-self and oxidize other elementsÂ
and Reducing agents being the opposite.Â