The correct option is B Jallianwala Bagh incident
General Colonel Reginald Edward Harry Dyer CB was an officer of the British Indian Army who, as a temporary brigadier-general, was responsible for the Jallianwala Bagh massacre in Amritsar. He enacted the Martial Law and ordered open fire on the public that had gathered in the Jallianwala Bagh on April 13, 1919.