In the given reaction ZnO + C —> Zn + CO, C is acting as a reducing agent.

A reducing agent is a substance that brings about the reduction of another substance by donating electrons. In this reaction, the carbon (C) is oxidized (loses electrons) and the zinc oxide (ZnO) is reduced (gains electrons).

Option 1 - C acting as an acid: This is not accurate as acids are substances that donate protons (H+ ions), and in this reaction, C is not involved in any proton donation.

Option 2 - C acting as a base: This is not accurate as bases are substances that accept protons (H+ ions), and C is not accepting any protons in this reaction.

Option 3 - C acting as an oxidizing agent: This is not accurate as an oxidizing agent is a substance that causes another substance to be oxidized (lose electrons), but in this reaction, C is itself being oxidized.

Option 4 - C acting as a reducing agent: This is the correct option. A reducing agent is a substance that causes another substance to be reduced (gain electrons), and in this reaction, C is donating electrons to the zinc oxide, causing