The correct answer is: a layer of aluminum oxide coats the metal surface.
Aluminum does not corrode because it forms a thin, protective layer of aluminum oxide on its surface when it is exposed to air. This layer of aluminum oxide is very thin, but it is very hard and resistant to corrosion. It is also electrically insulating, which means that it prevents the flow of electricity and prevents corrosion from occurring.
The formation of this protective layer of aluminum oxide is a self-healing process, which means that if the layer is damaged or scratched, it will quickly reform to protect the metal surface underneath. This is why aluminum is resistant to corrosion and why it is often used in a wide range of applications, including in the construction of buildings, aircraft, and automobiles.
The other options given in the question are not correct. An aluminum object is not a better oxidizing agent than iron, and aluminum is not coated with a stronger reducing agent.