Reactions involved in the smelting of iron in the blast furnace are given below. Arrange them in the correct sequence.
(1) `CaCO_3to CaO+CO_2+43kcal`
(2) `CaO+SiO_2toCasiO_3`
(3) ` C+O_2toCO_2+97kcal`
(4) `CO_2+CtoCO-39kcal`
(5) `FeO //Fe_2O_3+COtoFe+CO_2`
A. 34125
B. 31452
C. 54321
D. 23541