Final answer:
Galvanization, which involves coating iron or other metals with zinc, is used as a protective layer to prevent rusting because the zinc oxidizes before the underlying metal does.
Step-by-step explanation:
The method used as a protective layer on large or small stationary structures to prevent rusting is known as galvanization. This process involves coating iron or similar metals with a thin layer of a more easily oxidized metal, which is usually zinc. The zinc layer serves a dual purpose: it offers prophylactic protection by shielding the steel from oxygen in the air and also provides cathodic protection because zinc will oxidize before the underlying steel if exposed. Painting, epoxy coating, and zinc plating are other methods to prevent corrosion, but when considering a method that incorporates a more readily oxidized metal, galvanization is the correct answer.