After the Santhal Revolt (1855-56), the Santhal Pargana was created, carving out 5,500 square miles from which of the following districts?

Following the fierce Santhal Rebellion of 1855–56 led by Sidhu and Kanhu, the British administration acknowledged the grievances of the tribal population and passed the Santhal Parganas Tenancy Act. They created a separate non-regulation district called the 'Santhal Pargana', carving out roughly 5,500 square miles from parts of the Bhagalpur and Birbhum districts to prevent future unrest.