Step 1: Events Overview.
- Indus Water Treaty (D): Signed in 1960, it governs water distribution between India and Pakistan.
- Karachi Agreement (C): Signed in 1949, it established the ceasefire line in Kashmir after the first Indo-Pakistan war.
- Operation Gibraltar (A): Launched in 1965, it was Pakistan's attempt to infiltrate Jammu and Kashmir, triggering the second Indo-Pakistan war.
- Kargil War (B): Occurred in 1999 due to Pakistani forces infiltrating Kargil, resulting in armed conflict.
Step 2: Correct Sequence.
The chronological order of events is as follows:(A) D: Indus Water Treaty (1960)(B) C: Karachi Agreement (1949)(C) A: Operation Gibraltar (1965)(D) B: Kargil War (1999)
Step 3: Final Answer.
Therefore, the correct sequence is (B) A, C, B, D.