The correct answer is: a) Central Assam (Nagaon area).
The Davaka Kingdom was an ancient kingdom located in the Nagaon area of Central Assam. It was founded in the 6th century by King Davaka, who was a descendant of the Mahabharata hero Arjuna. The kingdom reached its peak under the rule of King Bhaskarvarman in the 7th century. Bhaskarvarman was a powerful ruler who expanded the kingdom’s territory and built many temples and monasteries. The Davaka Kingdom declined in the 8th century and was eventually conquered by the Pala Empire.
The other options are incorrect because:
- Upper Assam is a region in the north of Assam. It is home to the Brahmaputra River and the Kaziranga National Park.
- Lower Assam is a region in the south of Assam. It is home to the city of Guwahati and the Dibru-Saikhowa National Park.
- Barak Valley is a region in the south-east of Assam. It is home to the Barak River and the Silchar city.