Read the given passage and fill in the blanks by choosing an appropriate option.
Iron nails when new are grey and bright. When exposed to (i), they get covered with a (ii) coating. This process is called (iii) and it is a (iv) change.
|A||Moist air||Grey||Corrosion||Chemical, reversible|
|B||Air and water||Reddish brown||Rusting||Chemical, irreversible|
|C||Oxygen in air||Green||Rancidity||Physical, irreversible|
|D||Nitrogen in air||Reddish brown||Galvani-sation||Chemical, irreversible|