Correct Option
The correct option is Sadiya.
Explanation
The Brahmaputra river system is one of the largest in the world. Originating from the Chemayungdung glacier in Tibet (where it is known as the Tsangpo), it traverses eastward parallel to the Himalayas before taking a sharp southward turn to enter India.
Detailed Analysis
- Entry into India: The river crosses the Himalayas at the Namcha Barwa peak, taking a U-turn and carving a deep gorge. It enters India in the state of Arunachal Pradesh, where it is known as the Siang or Dihang.
- Geographical Reference: According to standard geographical, the river enters India west of Sadiya town in Arunachal Pradesh.
- Clarification on Location: While Sadiya is administratively located in the Tinsukia district of Assam today, historically and in the context of physical geography descriptions found in standard textbooks, it serves as the primary reference point for the river's descent into the plains. The river flows southwest and receives its main left-bank tributaries, the Dibang and the Lohit, near Sadiya, after which it is known as the Brahmaputra.
- Other Options:
- Pasighat: The river flows through Pasighat, where it emerges from the mountains into the plains, but the specific directional reference "west of" is associated with Sadiya in exam source materials.
- Tawang and Itanagar: These are located far from the river's entry point.
Key Takeaway
The Brahmaputra enters India as the Dihang (or Siang) and flows into the plains west of Sadiya. Sadiya is the key geographical marker for the confluence of the Dihang, Dibang, and Lohit rivers.