The Hunter Commission, appointed by the British Government, was tasked with investigating the Jallianwala Bagh tragedy. This incident occurred on April 13, 1919, in Amritsar, Punjab, during the period of British colonial rule in India.

Option 1: The Chauri Chaura incident refers to a violent clash that took place between the police and a mob of Indian protesters on February 4, 1922, in Chauri Chaura, Uttar Pradesh. The incident led to the death of 22 police officers, and Mahatma Gandhi called off the non-cooperation movement as a result. Therefore, this option is not related to the Hunter Commission.

Option 2: The Demolition of Kanpur Mosque does not relate to the Hunter Commission either. It refers to the demolition of a mosque by the British during the Rebellion of 1857, also known as the Indian Mutiny, as an act of punishment.

Option 3: The Jallianwala Bagh tragedy is the correct answer. On that fateful day, Brigadier General Reginald Dyer ordered his troops to open fire on a crowd of unarmed Indian protesters who had gathered at Jallianwala Bagh. The commission was appointed