The correct answer is: C. Spiti
Spiti is a district in the Indian state of Himachal Pradesh. It is the most sparsely populated district in India, with a population of just over 10,000 people. The district is located in the Trans-Himalayas, and is characterized by its high altitude, arid climate, and rugged terrain. The average annual rainfall in Spiti is just 100 mm, making it one of the driest regions in India.
The other options are incorrect because they are all located in the lower elevations of Himachal Pradesh, where the climate is more temperate and the rainfall is more abundant. Dharamshala, for example, receives an average annual rainfall of 1,200 mm. Shimla, the state capital, receives an average annual rainfall of 1,500 mm.
Spiti is a popular destination for trekking, mountaineering, and other outdoor activities. The district is also home to a number of Buddhist monasteries, which are popular tourist attractions.