The type of iron obtained from blast furnace in the extraction of iron is

The reactions which occur in blast furnace at $500-800 \mathrm{~K}$ during extraction of iron from haematite are

i. $3 \mathrm{Fe}_2 \mathrm{O}_3+\mathrm{CO} \longrightarrow 2 \mathrm{Fe}_3 \mathrm{O}_4+\mathrm{CO}_2$

ii. $\mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{C} \longrightarrow 2 \mathrm{Fe}+3 \mathrm{CO}$

iii. $\mathrm{Fe}_3 \mathrm{O}_4+4 \mathrm{CO} \longrightarrow \mathrm{Fe}+4 \mathrm{CO}_2$

iv. $\mathrm{Fe}_2 \mathrm{O}_3+\mathrm{CO} \longrightarrow 2 \mathrm{FeO}+\mathrm{CO}_2$

Lithium forms an alloy with ' $X$ '. This alloy is used to make armour plates. What is ' $X$ ' ?

Which one of the following sets in not correctly matched?