Here, the answer is D.
The method used to extract metals from the ore in which they are found depends on their reactivity. For example, reactive metals such as aluminium are extracted by electrolysis, while a less-reactive metal such as iron may be extracted by reduction with carbon or carbon monoxide.
The metals low in the reactive series are very less reactive. The oxides of such metals can be reduced to metals by heating alone e.g. mercury is obtained from its ore, cinnabar (HgS), by the process of heating.
Metals like iron, zinc, lead etc. occur as sulphides or carbonates in nature. First the ore is converted into its oxide form This is done by either roasting or by calcination. The metal oxide is reduced to metal by using suitable reducing agent such as Carbon.