The correct answer is option 1. galvanization.
The process of depositing a layer of zinc on iron is called Galvanization
Galvanization is a method used to protect iron and steel from corrosion by coating them with a layer of zinc. This process involves immersing the iron or steel object in a bath of molten zinc or applying zinc through electroplating. The zinc layer acts as a sacrificial anode, corroding preferentially to protect the underlying iron or steel substrate from rusting. Galvanization is commonly used to protect structural steel, fences, and other metal objects exposed to outdoor conditions. | 
