The correct answer is A. Spiti.
Spiti is a district in the Indian state of Himachal Pradesh. It is located in the north-eastern part of the state, bordering the Tibet Autonomous Region of China to the north and the Ladakh region of Jammu and Kashmir to the east. The district is known for its high altitude, arid climate, and Buddhist culture.
The Pin Valley is a valley located in the Spiti district. It is one of the most remote and sparsely populated valleys in India. The valley is home to a number of villages, as well as a number of Buddhist monasteries. The Pin Valley is a popular tourist destination, due to its stunning scenery and its unique culture.
The other options are incorrect because:
- Lahaul is a district in the Indian state of Himachal Pradesh. It is located in the north-western part of the state, bordering the Spiti district to the north and the Kullu district to the south. The district is known for its high altitude, arid climate, and Buddhist culture.
- Mandi is a district in the Indian state of Himachal Pradesh. It is located in the central part of the state, bordering the Kangra district to the north, the Kullu district to the east, the Shimla district to the south, and the Solan district to the west. The district is known for its temples, palaces, and gardens.
- Kaza is a town in the Indian state of Himachal Pradesh. It is the headquarters of the Spiti district. The town is located at an altitude of 3,600 meters (11,800 feet) above sea level. Kaza is a popular tourist destination, due to its stunning scenery and its unique culture.