Which Indian revolutionary assassinated Michael O'Dwyer?

Correct option is C

Udham Singh, an Indian revolutionary, assassinated Michael O'Dwyer.
 The Jallianwala Bagh Massacre, also known as the Massacre of Amritsar, was an incident that took place on April 13, 1919.
 On April 13, 1919, on Baisakhi day, a large crowd gathered in Jallianwala Bagh, unaware of the prohibitory orders in Amritsar. Brigadier-General Dyer arrived on the scene with his troops, surrounded the gathering, and blocked the only exit point.
 He then ordered his troops to open fire on the unarmed crowd, resulting in the death of over 1000 men, women, and children.
 The government set up the Hunter Commission to inquire into the massacre.
 Rabindranath Tagore gave up his knighthood.
 On 18 March, 1919, the British government passed Rowlatt Act. This Act allowed for speedy trials of offenses by a special court with no appeal and authorized the detention of political prisoners without trial for up to two years.
 Mahatma Gandhi returned his Kaiser-e-Hind in response to the Khilafat Movement.