Sardar Udham Singh killed whom?

Who from the following killed Michael O' Dwyer responsible for Jallianwala Bagh massacre?

Who led the Champaran Satyagraha in 1917 ?

Who saved the life of Gandhiji in Bihar during Champaran Satyagraha?

Who of the following called Gandhiji ‘’Mahatma’’ for the first time?

In which year Gandhi returned from South Africa?