Inside a blast furnace, iron ore is combined with coke and limestone, then heated in a stream of hot air. Compound R is produced. Compound R then reduces the iron ore to iron. Which equation shows how compound R is formed?
- A$\text{C} + \text{O}_2 \rightarrow \text{CO}_2$
- B$\text{CO}_2 + \text{C} \rightarrow 2\text{CO}$
- C$\text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2$
- D$\text{CaO} + \text{SiO}_2 \rightarrow \text{CaSiO}_3$