The correct answer is A. Kinnaur.
Kinnaur is a district in the Indian state of Himachal Pradesh. It is the least populous district in the state, with a population of just over 80,000 people. The district is located in the eastern part of the state, and is bordered by the states of Uttarakhand and Uttar Pradesh to the east, the district of Shimla to the south, the district of Lahaul and Spiti to the north, and the country of China to the east.
The district is a mountainous region, and is home to a number of glaciers and snow-capped peaks. The highest peak in the district is Kinnaur Kailash, which is located at an altitude of 6,800 meters. The district is also home to a number of rivers, including the Sutlej River, the Beas River, and the Ravi River.
The economy of Kinnaur is based on agriculture, forestry, and tourism. The main crops grown in the district are rice, wheat, barley, and maize. The district is also home to a number of forests, which are a source of timber and other forest products. Tourism is also a major source of income for the district, and the district is home to a number of tourist attractions, including the Kinnaur Kailash temple, the Nako Monastery, and the Kalpa Monastery.
As per Economic Survey 2018-19, Kinnaur has the least number of industrial units in the state. The district has only a few small-scale industries, and there are no large-scale industries in the district. The lack of industrial development in the district is due to a number of factors, including the remote location of the district, the lack of infrastructure, and the lack of skilled manpower.
The government of Himachal Pradesh has been trying to promote industrial development in the district, and has set up a number of incentives for investors. However, the lack of infrastructure and the lack of skilled manpower have been major obstacles to industrial development in the district.