Correct Option (D):
Siachen Glacier is situated to the north of the Nubra Valley.
- Siachen Glacier: It is located in the eastern Karakoram Range in the Himalayas and lies north of the Nubra Valley. It is one of the highest and coldest battlefields in the world.
- Nubra Valley: This valley lies to the south of the Siachen Glacier and is drained by the Nubra River, a tributary of the Shyok River.
Incorrect Options:
- East of Aksai Chin: Siachen Glacier lies to the west of Aksai Chin, not east.
- East of Leh: Siachen is located to the north of Leh, not east.
- North of Gilgit: Gilgit lies to the west of Siachen Glacier, so this is incorrect.