The best description of the Line of Control (LoC) in Kashmir is:
- It is a militarized border marked by a natural physical boundary.
The LoC separates Indian-administered Jammu and Kashmir from Pakistan-administered Azad Kashmir and Gilgit-Baltistan, and while it is heavily militarized, it does not function as a permanent border, and its delineation has historically been linked to natural features like rivers and mountains. The other options do not accurately represent the situation.