The correct answer is option 3: Jallianwala Bagh tragedy. The Hunter Commission was appointed by the Viceroy to investigate the Jallianwala Bagh Massacre that took place on 13th April 1919 in Amritsar, Punjab. The tragedy occurred when Brigadier General Reginald Dyer ordered his troops to open fire on a peaceful gathering of Indians who were protesting against the repressive Rowlatt Act. The commission, led by British judge Sir William Hunter, was tasked with examining the circumstances surrounding the massacre and determining the responsibility for the incident. It conducted interviews, collected evidence, and produced a report that was submitted to the British government. The report criticized Dyer`s actions but stopped short of holding him directly responsible for the massacre. The incident marked a turning point in India`s struggle for independence and led to widespread condemnation of British rule.