The correct answer is the Barak River.
The Barak River is a major river in northeastern India. It flows through the states of Manipur, Assam, and Tripura. The river is a major source of water for irrigation and drinking water in the region. It is also a popular destination for fishing and boating.
The Yu River is a tributary of the Barak River. It flows through the state of Manipur. The river is a major source of water for irrigation and drinking water in the region. It is also a popular destination for fishing and boating.
The Tuivai River is a tributary of the Barak River. It flows through the state of Manipur. The river is a major source of water for irrigation and drinking water in the region. It is also a popular destination for fishing and boating.
The Chindwin River is a major river in Myanmar. It flows through the states of Sagaing and Chin. The river is a major source of water for irrigation and drinking water in the region. It is also a popular destination for fishing and boating.
The Barak River is the only river among the given options that flows along a part of Manipur’s southern border. The Yu River, Tuivai River, and Chindwin River all flow through the state of Manipur, but they do not flow along the state’s southern border.