The correct answer is B) Air is blown into the chamber to convert pig iron to steel.
The diagram below is a schematic view of the Bessemer converter invented in 1855. The sentence that describes the way in which this object was used is "Air is blown into the chamber to convert pig iron to steel."
Henry Bessemer (1813-1898) was an English engineer and inventor who designed the Bessemer converter, a machine that allowed a cheaper method to produce steel. That is how molten pig iron was produced massively in manufacturing plants. Through oxidation, this invention could remove impurities.