The major commercial hubs and markets in Assam are located in cities like:

The correct answer is: d) All of the above.

Guwahati, Dibrugarh, Silchar, and Jorhat are the four major commercial hubs and markets in Assam. Guwahati is the largest city in Assam and the commercial capital of the state. It is a major transportation hub and is home to a number of industries, including tea, oil, and tourism. Dibrugarh is the second largest city in Assam and is a major center for trade and commerce. It is also home to a number of educational institutions and hospitals. Silchar is the third largest city in Assam and is a major center for trade and commerce. It is also home to a number of educational institutions and hospitals. Jorhat is the fourth largest city in Assam and is a major center for trade and commerce. It is also home to a number of educational institutions and hospitals.

Guwahati is located in the central part of Assam, on the banks of the Brahmaputra River. It is the largest city in the state, with a population of over 2 million people. Guwahati is a major transportation hub, with an international airport and a number of railway stations. The city is also home to a number of industries, including tea, oil, and tourism.

Dibrugarh is located in the eastern part of Assam, on the banks of the Brahmaputra River. It is the second largest city in the state, with a population of over 1 million people. Dibrugarh is a major center for trade and commerce. The city is also home to a number of educational institutions and hospitals.

Silchar is located in the south-eastern part of Assam, on the banks of the Barak River. It is the third largest city in the state, with a population of over 700,000 people. Silchar is a major center for trade and commerce. The city is also home to a number of educational institutions and hospitals.

Jorhat is located in the northern part of Assam, on the banks of the Brahmaputra River. It is the fourth largest city in the state, with a population of over 500,000 people. Jorhat is a major center for trade and commerce. The city is also home to a number of educational institutions and hospitals.