Option 1 refers to the Rowlatt Act of 1919, which incited popular indignation and led to the Jallianwala Bagh massacre. The enraged masses protested against this act`s unjust policies, and the resultant protests resulted in the tragic massacre.

Option 2 points out that Subhas Chandra Bose formed the Forward Bloc, a political group designed to unify anti-British forces in India, which is an accurate statement about his role in the movement.

Option 3 is true because Bhagat Singh, an influential figure in the Indian independence struggle, was indeed one of the founding members of the Hindustan Republican Socialist Association.

However, option 4 is not correct. The Karachi Session of the Indian National Congress in 1931 did not oppose the Gandhi-Irwin pact. Rather, it endorsed the pact, a political agreement signed by Mahatma Gandhi and then Viceroy Lord Irwin, hoping that it would set the base for further negotiations with the British. Hence, option 4 does not present a correct statement relating to the Indian independence struggle.