Arrange the following demographic milestones in the correct chronological order:

A) Child sex ratio falls below the overall sex ratio for the first time
(B) Age-specific sex ratios begin to be computed
(C) Child sex ratio declines to 919
(D) National Population Policy

(B) → (D) → (A) → (C)

The correct answer is Option 2: (B) → (D) → (A) → (C).

Age-specific sex ratios began to be computed in 1961. The National Population Policy was introduced in 2000. During the 2001 Census, the child sex ratio fell below the overall sex ratio for the first time. Finally, in the 2011 Census, the child sex ratio declined further to 919.