Step 1: Objective: Arrange four key events from colonial India's economic and social history chronologically.
Step 2: Event Chronology:
(B) Permanent Settlement: Introduced by Lord Cornwallis in 1793.
(A) Santhal Settlement in Rajmahal Hills: Encouraged post-Permanent Settlement for agriculture. Santhals settled in Damin-i-Koh from the early 1800s, formally demarcated in 1832. This event follows (B).
(D) Santhal Rebellion (Hul): Occurred in 1855-56 due to exploitation by moneylenders and zamindars.
(C) Cotton Boom: Began in 1861 following the American Civil War, which boosted Indian cotton exports.
Step 3: Conclusion: The correct chronological order of events is (B), (A), (D), (C).