Which reactions are oxidation-reduction reactions? check all that apply

options C and D

Explanation: in Redox reaction (oxidation-reduction), oxidation numbers of Reactant and product are different.

In oxidation, oxidation state increases and decreases in the case of Reduction.

In C, oxidation state of C is increased from +3 in C3H6 to +4 in CO2 hence oxidation and oxidation of O2 Decreased from 0 to -2 in H2O, hence Reduction. So it is a redox reaction

Similarly in D, Fe: +3 to 0

Carbon : +2 to +4.

the volume increases