The correct answer is (d) Brahmaputra.
The Brahmaputra is the main river in the Brahmaputra Valley. It is the ninth longest river in the world and the second longest river in India. The Brahmaputra originates in the Himalayas and flows through India, Bangladesh, and China. The river is a major source of water for irrigation and drinking water for millions of people. It is also a major transportation route.
The Brahmaputra has a number of tributaries, including the Barak, Manas, and Dhansiri. These tributaries help to shape the Brahmaputra Valley. The Barak is the largest tributary of the Brahmaputra. It originates in the Garo Hills of Meghalaya and flows through Assam and Bangladesh. The Manas is a tributary of the Brahmaputra that originates in the Himalayas and flows through Assam. The Dhansiri is a tributary of the Brahmaputra that originates in the Naga Hills of Nagaland and flows through Assam.
The Brahmaputra Valley is a fertile region that is home to a number of different ethnic groups. The valley is also home to a number of important historical and cultural sites. The Brahmaputra Valley is a beautiful and important region of India.