Explanation:

1. Forced cultivation of indigo and illegal taxation were significant grievances as peasants were compelled to grow indigo despite declining profits.

2. The increased rent burden added financial stress, exacerbating their hardships.

3. The Champaran Agrarian Act was an outcome, not a grievance.

4. Begar, or forced unpaid labor, highlighted the exploitation by colonial planters.

The correct answer is all options (1, 2, and 4) highlighting the various grievances documented.