The correct option is C They gathered to celebrate the Baisakhi festival.
On 13 April, 1919, Baisakhi day, nearly a thousand Sikhs assembled in Jallianwala Bagh, Amritsar to celebrate their festival. General Reginald Dyer and his troops arrived at the scene. 379 people were killed and over 1000 injured in the Jallianwalla Bagh massacre.