Karbi Anglong
Barak Valley
Nagaon
Upper Assam
Answer is Wrong!
Answer is Right!
The correct answer is: a) Karbi Anglong.
Sillimanite is a valuable refractory mineral that is found in the Karbi Anglong district of Assam. It is a hard, brittle mineral that is used in the manufacture of ceramics, glass, and refractory bricks. Sillimanite is also used as a filler in paints and plastics.
The other options are incorrect because they are not regions of Assam where sillimanite is found. Barak Valley is a region in the south of Assam, Nagaon is a district in the central part of Assam, and Upper Assam is a region in the north of Assam.