The correct answer is: B. Burhi Gandak
The Mandai dam project is a hydroelectric project that is being built on the Burhi Gandak river in the Indian state of Bihar. The project is being developed by the National Hydroelectric Power Corporation (NHPC) and is expected to be completed by 2023. The dam will have a power generation capacity of 240 MW and will irrigate an area of 12,000 hectares.
The Burhi Gandak is a tributary of the Ganges river. It originates in the Himalayas and flows through the states of Uttar Pradesh, Bihar, and Jharkhand. The river is a major source of water for irrigation and drinking water in the region.
The Mandai dam project has been controversial since its inception. Environmentalists have raised concerns about the impact of the dam on the environment and on the livelihoods of people living in the area. The project has also been opposed by some political parties.
Despite the controversy, the Mandai dam project is going ahead. The NHPC has said that the project will have a number of benefits for the region, including increased power generation, irrigation, and flood control.
The other options are incorrect because:
- Option A: The Koshi river is located in Nepal and India. It is the largest tributary of the Ganges river. The Koshi river is prone to floods and has caused extensive damage in the past.
- Option C: The Phalgu river is a tributary of the Ganges river. It flows through the state of Bihar. The Phalgu river is a sacred river for Hindus and is a popular destination for pilgrims.
- Option D: The North Koel river is a tributary of the Son river. It flows through the states of Jharkhand and Bihar. The North Koel river is a major source of water for irrigation and drinking water in the region.