In the reaction ZnO + C → Zn + CO, ‘C’ acts as

In the reaction ZnO + C → Zn + CO, ‘C’ acts as

an acid
a base
an oxidising agent
a reducing agent
This question was previously asked in
UPSC NDA-1 – 2015
In the reaction ZnO + C → Zn + CO, zinc oxide (ZnO) loses oxygen to become zinc (Zn), undergoing reduction. Carbon (C) gains oxygen to become carbon monoxide (CO), undergoing oxidation.
A reducing agent is a substance that causes another substance to be reduced, while it itself is oxidized. In this reaction, carbon (C) removes oxygen from ZnO, thus causing the reduction of ZnO. Carbon itself is oxidized in the process. Therefore, carbon acts as a reducing agent.
Conversely, an oxidising agent is a substance that causes another substance to be oxidized, while it itself is reduced. ZnO acts as the oxidising agent in this reaction because it provides oxygen for the oxidation of carbon and is itself reduced. This is a common method for the extraction of metals from their oxides using carbon as a reducing agent (smelting).