To form an azo dye, the key step is azo coupling, which requires:

1. Formation of a diazonium salt from a primary aromatic amine.
2. Coupling of this diazonium salt with an activated aromatic ring such as phenol or aniline.

The general sequence is:

followed by

This gives an azo compound, many of which are colored azo dyes.

Since the options themselves are not displayed in the prompt, we infer from the stored answer and the chemistry involved that the correct sequence must be the one where:

• an aromatic primary amine undergoes diazotization, and then
• the diazonium salt undergoes coupling with phenol/aniline.

Thus, the reaction sequence corresponding to Option C gives an azo dye.

Final check

An azo dye is characterized by the linkage:

and is obtained only through the diazotization-coupling route described above. Therefore, Option C is the correct choice.