The correct answer is: Tourism.
Tourism is the major industry of Ladakh. It is a popular tourist destination due to its stunning scenery, unique culture, and opportunities for adventure sports. The region is home to a number of historical and religious sites, as well as a variety of wildlife.
Cement is not a major industry in Ladakh. The region does not have the necessary resources to produce cement, and it would be prohibitively expensive to import it.
Apricot processing is a small-scale industry in Ladakh. Apricots are one of the main crops in the region, and they are used to make a variety of products, including dried apricots, apricot jam, and apricot brandy.
Woolen thread making is another small-scale industry in Ladakh. Wool is produced by sheep that are raised in the region, and it is used to make a variety of products, including clothing, blankets, and carpets.
Tourism is the major industry in Ladakh because it is a popular tourist destination. The region is home to a number of historical and religious sites, as well as a variety of wildlife. The scenery is also stunning, and there are many opportunities for adventure sports.