Capital of Assam is

Dispur
Guwahati
Karimganj
None of these

The correct answer is B. Guwahati.

Dispur is the capital of Assam, but it is not the most populous city. Guwahati is the most populous city in Assam and the largest city in the Northeast India. It is also the gateway to the Northeast India.

Karimganj is a city in Assam, India. It is the headquarters of Karimganj district. It is located on the banks of the Barak River. Karimganj is a major commercial and educational center in the Northeast India.

The other options are incorrect.