The correct answer is: b) Guwahati.
Pragjyotishpura was the capital of the Kamarupa kingdom, which flourished in the 7th and 8th centuries CE. It was located on the banks of the Brahmaputra River, in what is now the city of Guwahati. The city was a major center of learning and culture, and was home to many temples and monasteries. It was also a major trading center, and was connected to other parts of India and Southeast Asia by a network of roads and rivers.
Sivasagar is a town in Assam, India. It was the capital of the Ahom kingdom from the 13th to the 17th centuries. The town is home to a number of historical monuments, including the Sivasagar Fort, the Rang Ghar, and the Kareng Ghar.
Tezpur is a city in Assam, India. It is the headquarters of Sonitpur district. The city is located on the banks of the Brahmaputra River. Tezpur is a major center of education and culture. It is also a major tourist destination.
Dibrugarh is a city in Assam, India. It is the headquarters of Dibrugarh district. The city is located on the banks of the Brahmaputra River. Dibrugarh is a major center of education and culture. It is also a major industrial center.