Which of the following is the cathode in corrosion?

In the context of corrosion, the cathode is the site of a reduction reaction, where electrons are accepted. A metal that does not corrode can serve effectively as a cathode because it does not undergo oxidation (loss of electrons) in the corrosion process. This metal remains more stable and is less likely to react chemically with the surrounding environment.

Conversely, metals with a greater tendency to corrode are typically anodes and are involved in oxidation reactions, where they lose electrons and deteriorate. The conductive electrolyte facilitates the movement of ions, while an external electrical circuit involves other parts of the larger system but does not directly designate which metal acts as the cathode in corrosion. Thus, identifying a metal that does not corrode highlights its role as a cathode by understanding that corrosion occurs more readily in reactive (anodic) materials.