The specific chemical reaction sequence and the structures of the options are missing from the provided text. In the context of the Class 12 Chemistry curriculum for Amines and typical NEET questions, such multi-step reaction sequences usually involve conversions like the reduction of nitro compounds, diazotisation, coupling reactions, or the Hoffmann bromamide degradation. However, without the starting material and the specific reagents, the exact structure of the major product 'P' cannot be determined.