Major thermal power plants in Assam are located in:

Namrup and Bongaigaon
Dima Hasao
Tezpur
Silchar

The correct answer is: a) Namrup and Bongaigaon.

Namrup Thermal Power Station is a coal-fired power plant located in Namrup, Assam, India. It has an installed capacity of 2,100 MW. The plant was commissioned in 1983.

Bongaigaon Thermal Power Station is a coal-fired power plant located in Bongaigaon, Assam, India. It has an installed capacity of 2,000 MW. The plant was commissioned in 1985.

Dima Hasao is a district in the state of Assam, India. It is located in the north-eastern part of the state. The district has a population of about 1.5 million people. The main towns in the district are Haflong and Maibang.

Tezpur is a city in the state of Assam, India. It is located in the north-eastern part of the state. The city has a population of about 300,000 people. Tezpur is the headquarters of Sonitpur district.

Silchar is a city in the state of Assam, India. It is located in the south-eastern part of the state. The city has a population of about 250,000 people. Silchar is the headquarters of Cachar district.

The major thermal power plants in Assam are located in Namrup and Bongaigaon. These plants are coal-fired and have an installed capacity of 2,100 MW and 2,000 MW, respectively. The plants were commissioned in 1983 and 1985, respectively.