The correct answer is (a) West Khasi Hills.
Sillimanite is a valuable mineral used in refractories, which are materials that can withstand high temperatures. It is found in the West Khasi Hills of Meghalaya, India. The West Khasi Hills are a mountainous region in the northeastern part of the state. They are home to a number of different ethnic groups, including the Khasis, Jaintias, and Garos. The region is known for its beautiful scenery, including its forests, waterfalls, and lakes.
The West Khasi Hills are also home to a number of important mineral deposits, including sillimanite. Sillimanite is a type of aluminum silicate mineral that is found in metamorphic rocks. It is a valuable mineral because it is resistant to heat and corrosion. It is used in a variety of applications, including the manufacture of refractories, ceramics, and glass.
The West Khasi Hills are a beautiful and important region of Meghalaya. They are home to a number of different ethnic groups, as well as a number of important mineral deposits. Sillimanite is one of the most valuable minerals found in the region, and it is used in a variety of applications.