In order to avenge whom, Bhagat Singh and his associates killed the British officer John Saunders?
A. Death of Ramprasad Bismil
B. Villagers' death in Chauri Chaura incident
C. Death of Lala Lajpat Rai
D. Massacre at Jallianwala Bagh
1. A
2. C
3. B
4. D