Explanation:

Swaraj (Correct): The fundamental difference between the Moderates and Extremists within the Indian National Congress primarily revolved around the concept and methods of achieving 'Swaraj' (self-rule). Moderates believed in constitutional agitation and gradual reforms to achieve self-government within the British Empire. Extremists advocated for complete Swaraj (full independence) and were willing to employ more assertive methods like mass mobilization and passive resistance. The Surat Split of 1907 was a direct consequence of these divergent views on the ultimate political objective. Swadeshi: This was a key method advocated by Extremists, which Moderates supported to some extent but were hesitant about its aggressive application. Boycott: This was another tool championed by Extremists, which Moderates generally opposed as too radical. National Education: Extremists promoted National Education as an alternative, while Moderates were less keen on a complete overhaul of existing institutions. These were methods, not the core ideological difference.