First Major Challenge to British Authority in Bengal
The Sanyasi Rebellion, spanning from 1763 to 1800, is recognized as the initial significant challenge to the British administration in the Bengal region.
Analysis of Options:
- Sanyasi Rebellion (1763-1800): This revolt occurred earliest and involved a broad spectrum of society, directly confronting British policies and authority in Bengal.
- Santhal Rebellion (1855–56): Occurred much later in the 19th century.
- Indigo Revolt (1859–60): Took place in the mid-19th century, focusing specifically on oppressive indigo cultivation practices.
- Moplah Rebellion (1921): Occurred in the early 20th century in the Malabar region, not Bengal.
Therefore, the Sanyasi Rebellion represents the first major challenge to British authority in Bengal among the choices provided due to its timing and scale.