The correct answer is C. Galvanizing.
Galvanizing is the process of applying a protective zinc coating to iron or steel objects to prevent them from rusting. The zinc coating acts as a sacrificial anode, meaning that it will corrode instead of the iron or steel object, thus protecting it from rust.
Hot dipping is a process of coating steel or iron objects with molten zinc. The objects are dipped into a bath of molten zinc, which coats them evenly. This process is often used to coat large objects, such as pipes and beams.
Tinning is a process of coating steel or iron objects with tin. The objects are dipped into a bath of molten tin, which coats them evenly. This process is often used to coat cans and other food containers.
Electroplating is a process of coating an object with a thin layer of metal by passing an electric current through a solution containing the metal ions. This process is often used to coat jewelry and other decorative objects.