Correct Answer: Option A) 1 & 2 only
Statement 1: "The Subansiri, Manas, Kameng, and Sankosh are right bank tributaries of the Brahmaputra."
This is correct. The Brahmaputra flows from west to east in Assam, and these rivers join it from the north (right bank). The Subansiri, Manas, Kameng, and Sankosh all originate in the Himalayas and flow southward to join the Brahmaputra from its right bank.
Statement 2: "The Manas River forms a part of the boundary between Bhutan and India."
This is correct. The Manas River serves as an international boundary between Bhutan and India for part of its course. It originates in Bhutan as Mangde Chhu and later forms the border between Bhutan and the Indian state of Assam.
Statement 3: "All tributaries of the Brahmaputra originate in Tibet."
This is incorrect. While some major tributaries like Dibang, Lohit, and Subansiri do originate in Tibet, many others originate in different regions:
The Manas, Sankosh, and Kameng originate in Bhutan and Arunachal Pradesh
The Dhansiri, Kopili, and Barak originate in the hills of Nagaland, Meghalaya, and Manipur
Various tributaries originate in the Patkai hills and other ranges of Northeast India
