Out of C and CO, which is a better reducing agent at the lower temperature range in the blast furnace to extract iron from the oxide ore?

Explanation

Ellingham diagram for oxides of metals and carbon shows
`C_((s)) + O_(2(g)) rarr CO_(2(g))` (i)
`2C_((s)) + O_(2(g)) rarr 2CO_((g))` (ii)
`2CO_((g)) + O_(2(g)) rarr 2CO_(2(g))` (iii)
that at 673K, `Delta_(f) G^(@) (CO_(2)) lt Delta_(f) G^(@) (CO)` hence formation of `CO_(2)` gas is more favourable than CO gas. Hence, out of C and CO, CO is a better reducing agent.