Step 1: Understanding the Events Chronologically.
- The Indus Water Treaty (D) was signed in 1960 to manage water-sharing between India and Pakistan.
- The Karachi Agreement (C) was signed in 1949 to establish a ceasefire line in Kashmir after the first Indo-Pakistan war.
- Operation Gibraltar (A) took place in 1965 as an attempt by Pakistan to infiltrate Jammu and Kashmir, leading to the second Indo-Pakistan war.
- The Kargil War (B) occurred in 1999 when Pakistani forces infiltrated Kargil, leading to conflict between India and Pakistan in the region.
Step 2: Chronological Order.
The correct chronological order is:
(A) D: Indus Water Treaty (1960)
(B) C: Karachi Agreement (1949)
(C) A: Operation Gibraltar (1965)
(D) B: Kargil War (1999)
Step 3: Conclusion.
Thus, the correct answer is (B) A, C, B, D.