The Loktak Hydroelectric Project is a major source of power in Manipur and is located on the:

Manipur River
Imphal River
Barak River
Yu River

The correct answer is: The Loktak Hydroelectric Project is a major source of power in Manipur and is located on the Imphal River.

The Imphal River is a river in Manipur, India. It is the longest river in the state, flowing for about 200 kilometers (120 mi). The river originates in the Manipur Hills and flows through the Imphal Valley before joining the Barak River. The Imphal River is a major source of water for irrigation and drinking water in Manipur. It is also a popular destination for fishing and boating.

The Loktak Hydroelectric Project is a hydroelectric power plant located on the Imphal River in Manipur, India. The plant has a capacity of 105 megawatts and was commissioned in 1974. The Loktak Hydroelectric Project is a major source of power in Manipur.

The other options are incorrect. The Manipur River is a river in Manipur, India. It is a tributary of the Barak River. The Barak River is a river in India and Bangladesh. It is the largest river in the Barak Valley. The Yu River is a river in Manipur, India. It is a tributary of the Imphal River.