Among the reactions (a) - (d), the reaction(s) that does/do not occur in the blast furnace during the extraction of iron is/are :
(a) CaO + SiO₂ $$ \to $$ CaSiO₃
(b) 3Fe₂O₃ + CO $$ \to $$ 2Fe₃O₄ + CO₂
(c) FeO + SiO₂ $$ \to $$ FeSiO₃
(d) FeO $$ \to $$ Fe + $${{1 \over 2}}$$O₂

The refining method used when the metal and the impurities have low and high melting temperatures, respectively, is :

The purest from of commercial iron is :

The correct statement is :