The largest city and commercial hub of Assam is:

Tezpur
Silchar
Guwahati
Jorhat

The correct answer is c) Guwahati.

Guwahati is the largest city and commercial hub of Assam. It is the most populous city in the Northeast India with a population of over 2 million. It is also the gateway to the Northeast India. Guwahati is located on the banks of the Brahmaputra River. It is a major transportation hub and is well connected by air, rail and road. The city is home to many educational institutions, hospitals, and IT companies. Guwahati is also a popular tourist destination. Some of the popular tourist attractions in Guwahati include the Kamakhya Temple, the Umananda Temple, the Assam State Zoo, and the Guwahati Aquarium.

Tezpur is a city in the Sonitpur district of Assam, India. It is the headquarters of the Sonitpur district. Tezpur is located on the banks of the Brahmaputra River. It is a major educational and cultural center in Assam. Tezpur is also a popular tourist destination. Some of the popular tourist attractions in Tezpur include the Tezpur University, the Tezpur Zoo, and the Rang Ghar.

Silchar is a city in the Cachar district of Assam, India. It is the headquarters of the Cachar district. Silchar is located on the banks of the Barak River. It is the second largest city in Assam after Guwahati. Silchar is a major commercial and educational center in Assam. It is also a popular tourist destination. Some of the popular tourist attractions in Silchar include the Silchar Medical College and Hospital, the Silchar University, and the Silchar Zoo.

Jorhat is a city in the Jorhat district of Assam, India. It is the headquarters of the Jorhat district. Jorhat is located on the banks of the Brahmaputra River. It is the third largest city in Assam after Guwahati and Silchar. Jorhat is a major commercial and educational center in Assam. It is also a popular tourist destination. Some of the popular tourist attractions in Jorhat include the Jorhat University, the Jorhat Tea Auction Centre, and the Jorhat Zoo.