The correct answer is (d), Uttarakhand.
The Nelong Valley is a valley in the Garhwal Himalayas in the Indian state of Uttarakhand. It is located in the Chamoli district, about 200 kilometers from the state capital, Dehradun. The valley is about 50 kilometers long and 10 kilometers wide, and is surrounded by mountains on all sides. The main river in the valley is the Nelong River, which flows from the glaciers in the Himalayas to the Ganges River. The valley is home to a number of villages, and is a popular tourist destination.
The other options are incorrect. Himachal Pradesh is a state in the Indian Himalayas. Sikkim is a state in the eastern Himalayas. Jammu and Kashmir is a state in the northwestern Himalayas.