Which of the following reason was responsible for the Santhal Revolt (1855-56)?

All of the above.

The Santhals, however, soon found that the land they had brought under cultivation was slipping away from their hands. The state was levying heavy taxes on the land that the Santhals had cleared, moneylenders (dikus) were charging them high rates of interest and taking over the land when debts remained unpaid, and zamindars were asserting control over the Damin area.