The correct option is C Udham Singh
The Jallianwala Bagh massacre took place on 13 April 1919 when troops of the British Indian Army under the command of General Dyer fired rifles into a crowd of Baisakhi pilgrims, who had gathered in Jallianwala Bagh, Amritsar, Punjab. Udham Singh was a Punjab revolutionary and freedom fighter belonging to the Ghadar Party. He assassinated Michael O' Dwyer, the former Lieutenant Governor of Punjab on 13th March 1940 to avenge the Jallianwala Bagh massacre.