Shimla Agreement

Question:
Consider the following statements regarding the outcomes of the Shimla Agreement:

1. The Line of Control (LoC) replaced the International Border between India and Pakistan in Jammu and Kashmir, with both countries recognizing it as permanent.
2. India returned over 13,000 km² of territory captured during the 1971 war, but retained strategic locations such as Turtuk and Tyakshi in the Chorbat Valley.
3. Both nations agreed not to alter the Line of Control unilaterally, though disagreements over interpretation persisted.

Which of the above statements is/are correct?
A) 1 and 2 only
B) 2 and 3 only
C) 1 and 3 only
D) 1, 2, and 3