Which of the following is a common method used to prevent iron from rusting?

Coating iron with a special paint is an effective method to prevent rusting because it creates a barrier between the iron surface and environmental factors such as moisture and oxygen, both of which are essential for the corrosion process. Rusting is an electrochemical reaction that occurs when iron reacts with oxygen in the presence of water; by applying a protective layer of paint, the metal is shielded from these corrosive elements.

The paint must be durable to withstand wear and tear and should fully cover the iron to be effective. This method is commonly used in various applications, such as automotive parts and outdoor structures, to prolong the life of iron products and maintain their integrity and appearance. The other methods listed do not provide the same level of protection. For instance, removing air exposure completely is impractical, exposing iron to moisture accelerates rusting, and non-corrosive environments are not always feasible. Therefore, coating with paint stands out as a proactive and practical solution to inhibit rust formation.