The given reaction involves a diazonium salt reacting with an aromatic amine under acidic conditions to form a colored compound, typically a dye. This type of reaction is known as an azo coupling reaction.
The reaction can be summarized as follows:
1. **Formation of Diazonium Ion**: The given reactant is a diazonium salt, which is typically formed from an aromatic amine using sodium nitrite (NaNO2) and hydrochloric acid (HCl) under cold conditions.
2. **Azo Coupling Reaction**: The diazonium ion acts as an electrophile, and it couples with an amine to form an azo compound. In this case, the amine used is aniline (C6H5NH2).
3. **Formation of Azo Dye**: The product (A) is an azo compound, which is characterized by the presence of an azo group (-N=N-) linking two aromatic rings.
The product is a yellow azo dye, and its structure involves the diazonium group attaching to the para position of the benzene ring of aniline.
Therefore, the correct product (A) is the azo dye shown in the image above.
