At the temperature corresponding to which of the points in Fig. `FeO`

At the temperature corresponding to which of the points in Fig. `FeO` will be reduced to Fe by coupling the reaction `2Fe rarr 2Fe +O_(2)` with all of the following reactions? (a) `C + O_(2) rarr CO_(2)` (b) `2C +O_(2) rarr 2CO` and (c) `2CO +O_(2) rarr 2CO_(2)`

`FeO`