A silver article turns black when kept open in air for few days. The article when rubbed with toothpaste again starts shining because

A

Hydrogen peroxide present in the toothpaste reacts to give silver sulphate.

B

Hydrated silica present in the toothpaste reacts to give silver oxide.

C

Aluminium hydroxide present in the toothpaste reacts to give silver hydroxide.

D

Calcium carbonate present in the toothpaste reacts to give silver carbonate.