Sean fell while riding his green bicycle last year. He bent the fender and scratched the paint down to the metal. Sean’s bicycle was outside all winter and now is beginning to rust where the fender is damaged. Which evidence tells Sean that a chemical change is taking place on his bike?

*
The paint is scratched.
The metal fender is bent.
The metal is beginning to turn orange.
The bicycle sat in the weather all winter.

The metal is beginning to turn orange.