The correct answer is c) Guwahati.
Guwahati is the largest city in Assam, India. It is the most populous city in the northeastern region of India with a population of 2,932,442 in 2011. Guwahati is the seat of the Government of Assam and the headquarters of Guwahati district. The city is located on the south bank of the Brahmaputra River.
Silchar is the second largest city in Assam, India. It is the headquarters of Cachar district. The city is located on the banks of the Barak River. Silchar has a population of 2,401,442 in 2011.
Jorhat is the third largest city in Assam, India. It is the headquarters of Jorhat district. The city is located on the banks of the Brahmaputra River. Jorhat has a population of 1,390,604 in 2011.
Dibrugarh is the fourth largest city in Assam, India. It is the headquarters of Dibrugarh district. The city is located on the banks of the Brahmaputra River. Dibrugarh has a population of 1,265,000 in 2011.
The population of Guwahati is more than twice the population of Silchar, Jorhat, and Dibrugarh combined. This is because Guwahati is a major commercial and industrial center. It is also a major educational and cultural center.