Which of the following are the steps/reactions involved in the extraction of iron?

Iron(III) oxide's $\left(F{e}_2{O}_3\right)$ combination with carbon monoxide $\left(\mathrm{CO}\right)$ to produce iron $\left(\mathrm{Fe}\right)$ and carbon dioxide $\left(C{O}_2\right)$ is a redox reaction because both iron reduction and carbon monoxide oxidation are occurring.The following reaction obtained during extraction of iron,

$3{\mathrm{Fe}}_2{\mathrm{O}}_3+\mathrm{CO}\stackrel{\mathrm{\Delta }}{\to }2{\mathrm{Fe}}_3{\mathrm{O}}_4+{\mathrm{CO}}_2$

${\mathrm{Fe}}_3{\mathrm{O}}_4+\mathrm{CO}\stackrel{\mathrm{\Delta }}{\to }3\mathrm{FeO}+{\mathrm{CO}}_2$

$\mathrm{FeO}+\mathrm{CO}\stackrel{\mathrm{\Delta }}{⟶}\mathrm{Fe}+{\mathrm{CO}}_2$

After the above reaction calcium silicate is produced as slag.

Hence options A,B,C and D are correct.