Which of the following statements is not correct about the rusting of iron?

• A
  Coating of iron surface by tin prevents rusting,even if the tin coating is peeling off.
• B
  When $pH$ lies above $9$ or $10$,the rusting of iron does not take place.
• C
  Dissolved acidic oxides like $SO_2$ and $NO_2$ in water act as catalysts in the process of rusting.
• D
  Rusting of iron is envisaged as the setting up of an electrochemical cell on the surface of the iron object.