In iron (III) oxide, iron has an oxidation state of +3. In iron (in products), iron has an oxidation state of 0. So iron is reduced, which means it has gained electrons. So A is wrong.
The oxide ions in iron (III) oxide each have a charge of -2. So B is wrong.
Iron (III) oxide oxidises carbon in CO. In CO, carbon has an oxidation state of +2 but in carbon monoxide, it has an oxidation state of +4. So Iron (III) oxide oxidises carbon from +2 to +4. So, Iron (III) oxide is an oxidising agent. C is the answer.
The value of ∆H is negative which indicates that this process is exothermic. D is wrong.
Electric current is not used in this reaction so this is not an example of electrolysis. So E is wrong.