Which of the following revolutionary groups' members assassinated Assistant Superintendent of Police John Saunders in 1927?

Hindustan Republican Association

The correct answer is Option 2 - Hindustan Republican Association

The members of the Hindustan Republican Association (HRA) assassinated Assistant Superintendent of Police John Saunders in 1927.

The HRA was a revolutionary organization founded in 1923 by Chandrashekhar Azad, Bhagat Singh, and Sukhdev Thapar. It was one of the most active revolutionary groups in India during the British colonial period. The HRA was responsible for a number of assassinations and bombings, including the assassination of Saunders.

Saunders was assassinated by Bhagat Singh and Shivaram Rajguru on December 17, 1927, in Lahore, India. The assassination was in retaliation for the death of Lala Lajpat Rai, a prominent Indian leader who had died earlier that year after being lathi-charged by the British police.

The assassination of Saunders was a major event in the Indian independence movement. It showed the British that the Indians were willing to fight for their freedom, even at the cost of their own lives.

The other three organizations listed in your question, Hindustan Sewa Dal, Abhinav Bharat Secret Society, and Anushilan Samiti, were also revolutionary organizations, but they were not involved in the assassination of Saunders.