- Assertion (A) is true: The early phase of the Indian national movement (roughly 1870-1900), dominated by the Moderates, focused on educating Indians about political issues, spreading nationalist ideas among the public, and articulating a political ideology based on constitutional methods. This period was crucial for building a national consciousness and political identity. - Reason (R) is true: The press was indeed a vital tool for the early nationalists. Newspapers and journals like 'The Hindu', 'Swadesamitran', 'Bengalee', 'Amrita Bazar Patrika', 'Indian Mirror', 'Kesari', and 'Mahratta' were used extensively to criticize government policies, articulate grievances, and spread nationalist messages, thereby facilitating politicisation and propaganda. - Relationship: Reason (R) provides the primary method or instrument (the press) through which the task described in Assertion (A) (politicisation, propaganda, and propagation of ideology) was effectively carried out by the early national movement leaders. Therefore, (R) correctly explains (A).