Identify the river on the basis of the following information: It has an antecedent drainage system. It enters India through Arunachal Pradesh. It forms large riverine islands and is associated with frequent floods in Assam. It joins the Ganga system before draining into the Bay of Bengal. Which one of the following rivers is described above?

The correct answer is Option 2 . Key Points Option A: The Indus has an antecedent drainage system, but it does not enter India through Arunachal Pradesh and is not associated with large riverine islands in Assam. Hence, Option A is incorrect . Option B: The Brahmaputra has an antecedent drainage system . It enters India through Arunachal Pradesh as the Siang/Dihang , forms large riverine islands such as Majuli in Assam, causes frequent floods, and later joins the Ganga system in Bangladesh before draining into the Bay of Bengal. Hence, Option B is correct . Option C: The Teesta is an important Himalayan river, but it does not enter India through Arunachal Pradesh and is not the river described here. Hence, Option C is incorrect . Option D: The Mahanadi is a peninsular river and does not have the given Himalayan antecedent drainage characteristics. Hence, Option D is incorrect . Therefore, the river described above is the Brahmaputra . Additional Information The Brahmaputra is known as Tsangpo in Tibet. It enters Arunachal Pradesh as Siang/Dihang . In Assam, it is joined by tributaries such as Dibang, Lohit, Subansiri and Manas . It forms large riverine islands, including Majuli . In Bangladesh, it is known as Jamuna and joins the Ganga-Padma system.