The correct answer is D. Kinnaur.
Hangrang valley is a valley in the Kinnaur district of Himachal Pradesh, India. It is located in the eastern part of the district, and is bounded by the Zanskar Range to the north and the Himalayas to the south. The valley is home to a number of villages, including Hangrang, Kalpa, and Nako. The Hangrang River flows through the valley, and the valley is also home to a number of glaciers, including the Pin Parvati Glacier.
The Hangrang valley is a popular tourist destination, and is known for its beautiful scenery, its Buddhist monasteries, and its traditional culture. The valley is also a popular destination for trekking and mountaineering.
Option A is incorrect because Sangla is a district in Himachal Pradesh, but it is not the district in which Hangrang valley is located.
Option B is incorrect because Hamirpur is a district in Himachal Pradesh, but it is not the district in which Hangrang valley is located.
Option C is incorrect because Una is a district in Himachal Pradesh, but it is not the district in which Hangrang valley is located.