The primary aim of the Swarajya Party was to obstruct and undermine the reforms introduced in 1919. Option 1 which states that the aim was to cooperate with the government in implementing the reforms is incorrect. The Swarajya Party did not support the reforms and sought to oppose them. Option 2 which suggests that the aim was to gain experience of the functioning of representative government is also incorrect. The Swarajya Party was not interested in gaining experience, but rather in opposing and obstructing the reforms. Option 4 which states that the aim was to exhibit displeasure over the failure of the non-cooperation movement is also incorrect. While the Swarajya Party was disappointed with the failure of the non-cooperation movement, their primary aim was not to exhibit displeasure, but to obstruct the reforms. Therefore, option 3 accurately represents the primary aim of the Swarajya Party, which was to wreck the scheme of the 1919 reforms through continuous and consistent obstruction.