Answer:

Introduction:
Common salt, also known as sodium chloride (NaCl), is a versatile compound that has various applications apart from its common use in the kitchen. It can be used as a raw material for the production of different chemicals and substances. In this case, common salt can be used as a raw material for making bleaching powder.

Bleaching Powder:
Bleaching powder, also known as calcium hypochlorite (Ca(ClO)2), is a chemical compound widely used for bleaching, disinfecting, and sanitizing purposes. It is produced by the reaction between calcium hydroxide (slaked lime) and chlorine gas. However, before this reaction takes place, chlorine gas needs to be prepared, and this is where common salt comes into play.

Preparation of Bleaching Powder:
The production of bleaching powder involves several steps:

1. Preparation of chlorine gas:
- Chlorine gas is prepared by the electrolysis of a solution of common salt (sodium chloride).
- When an electric current is passed through the salt solution, chlorine gas is liberated at the anode (positive electrode).

2. Reaction between chlorine gas and slaked lime:
- The chlorine gas obtained in the previous step is then reacted with slaked lime (calcium hydroxide).
- This reaction produces bleaching powder (calcium hypochlorite) along with water.

The chemical equation for the reaction is as follows:
Ca(OH)2 + 2Cl2 → Ca(ClO)2 + H2O

Conclusion:
In conclusion, common salt (sodium chloride) can be used as a raw material for making bleaching powder (calcium hypochlorite). The production of bleaching powder involves the preparation of chlorine gas, which is obtained by the electrolysis of a salt solution. This chlorine gas is then reacted with slaked lime to produce bleaching powder. Therefore, the correct answer to the given question is option 'B' - common salt can be used as a raw material for making bleaching powder.