Which of the following reaction occurs during smelting in the blast furnace at the lowest temperature in the extraction of iron. 

• A

  $\mathrm{CaO}+{\mathrm{SiO}}_2\to {\mathrm{CaSiO}}_3$

• B

  ${\mathrm{Fe}}_2{\mathrm{O}}_3+3\mathrm{C}\to 2\mathrm{Fe}+3\mathrm{CO}$

• C

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

• D

  ${\mathrm{CO}}_2+\mathrm{C}\to 2\mathrm{CO}$