Smelting of iron ore involves a) oxidizing iron to ferric oxide and then adding silicon and boron b) dissolving the ore in hot water to separate iron and aluminum c) heating beyond iron's melting point and combining the material with carbon d) crushing and heating the ore at its melting point e) washing the ore with acid to extract iron.

(C) heating beyond iron's melting point and combining the material with carbon.

Explanation: The traditional method of iron production, consisting of gathering iron ore and then smelting it in a clay shaft full of burning charcoal (carbon). The result is a spongy mass of white hot iron, which then needs to be hammered, folded and welded until it is refined. Impurities are melted out of the ore in the form of iron silicates.