The correct answer is: D. Mahendragarh
Kyanite is a blue, green, or white aluminum silicate mineral that is used in a variety of industrial applications. It is found in metamorphic rocks, and its deposits are often associated with other minerals such as feldspar, quartz, and mica.
The districts of Hisar, Ambala, and Rohtak do not have deposits of kyanite. However, the district of Mahendragarh does have deposits of kyanite. In fact, Mahendragarh is one of the major producers of kyanite in India.
The kyanite deposits in Mahendragarh are located in the Aravalli Range. The deposits are found in the form of veins and lenses in gneiss and granite rocks. The kyanite is mined by open-pit methods.
The kyanite from Mahendragarh is used in a variety of industrial applications, including the manufacture of ceramics, refractories, and abrasives. It is also used in the production of aluminum and other metals.
The kyanite industry in Mahendragarh is an important part of the local economy. The industry employs thousands of people and generates millions of dollars in revenue each year.