The correct answer is option 2, Calcutta. Swarajya was declared as the goal of the Congress at its session held in 1906 in Calcutta. Swarajya, which means self-rule or self-governance, was a key objective of the Indian National Congress in their struggle for independence from British colonial rule. The Congress session in Calcutta in 1906 is significant because it marked a shift in the Congress`s approach towards demanding full independence, as opposed to their earlier focus on constitutional reforms. This declaration of Swarajya as the goal of the Congress further energized the nationalist movement in India and set the stage for future independence movements. It is important to note that the other options, Bombay, Lucknow, and Madras, were not the locations where Swarajya was declared as the goal of the Congress.