(A) Reduction with carbon
The most common method of extracting metals from their oxide ores is reduction with carbon (coke). Metals in the middle of the activity series (Zn, Fe, Pb, Cu) are commonly extracted this way, e.g., ZnO + C → Zn + CO.
Source: Metals and Non-metals, Section 3.4.4
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The textbook (Fig. 3.9 and Section 3.4.4) clearly states that Zn, Fe, Pb, Cu — the largest group of commercially important metals — are extracted by reduction using carbon. Electrolytic reduction is used only for highly reactive metals (K, Na, Ca, Mg, Al), which is a special case, not the "most common" method. Reduction with Al (thermite) and H₂ are used in specific/limited cases only. Carbon (coke) is cheap and widely used, making option (A) correct.