The reaction involves the diazotization of sulphanilic acid, which forms a diazonium salt. This diazonium salt then couples with the compound \( C_6H_5NH_2 \), leading to the formation of the azo-dye product \( Y \).
The structure of \( Y \) matches option (4) in which the diazonium ion is coupled with the benzene ring of \( C_6H_5NH_2 \), forming the characteristic azo linkage (\(-N=N-\)) between the two aromatic rings.
Thus, the correct answer is: Option (4)
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