The correct answer is D. All of the above.
Kothagudem Thermal Power Station is a coal-fired power plant located in Kothagudem district of Telangana, India. It has an installed capacity of 2,100 MW.
Singareni Thermal Power Plant is a coal-fired power plant located in Karimnagar district of Telangana, India. It has an installed capacity of 2,400 MW.
Ramagundam Thermal Power Station is a coal-fired power plant located in Karimnagar district of Telangana, India. It has an installed capacity of 2,100 MW.
These three power plants are the major thermal power plants located in Telangana. They are all owned and operated by the state-owned power company, Telangana State Power Generation Corporation Limited (TSGENCO).