(B) Al, Al₂O₃
Aluminium is used in the thermite process (Fe₂O₃ + 2Al → 2Fe + Al₂O₃). When heated in air, it forms Al₂O₃, which is amphoteric — reacting with both acids and bases.
Source: Chapter 3, Sections 3.2.1 and 3.4.4
Two clues identify the metal: (1) use in the thermite reaction — the textbook explicitly states aluminium reduces Fe₂O₃ in the thermit reaction; (2) the oxide must be amphoteric — the textbook names Al₂O₃ and ZnO as the amphoteric oxides. Only option (B) satisfies both conditions. Fe₂O₃ is basic, not amphoteric, so (C) is wrong despite iron being involved in the thermite reaction.