The correct answer is: A. Galvanisation
Galvanisation is the process of protecting iron or steel from rust by coating it with a thin layer of zinc. The zinc forms a barrier between the iron and the oxygen in the air, preventing the iron from rusting.
Corrosion is the process of deterioration of a material due to chemical or electrochemical reaction with its environment. Rusting is a form of corrosion that occurs when iron or steel is exposed to oxygen and water.
Sublimation is the process of a substance changing directly from a solid to a gas without passing through the liquid state.
Reduction is a chemical reaction in which an atom or ion gains electrons.
In conclusion, the process of preventing iron from rusting by coating it with zinc is called galvanisation.