The correct answer is Brahmaputra. Explanation & Key Takeaways: • The Lohit River is a major tributary of the Brahmaputra River and is located in the northeastern region of India. • The river originates in the Zayal Chu range of the Eastern Tibet region, in China. After flowing through the mountainous regions of Arunachal Pradesh, it eventually merges with the Brahmaputra River near the Assam-Arunachal Pradesh border. • The Lohit River carries a significant amount of water and sediment, contributing to the flow and volume of the Brahmaputra River. Hence, the correct answer is Brahmaputra. • The Brahmaputra River is one of the major rivers of the Indian subcontinent. It is known for its vast basin and flows through multiple countries, including China, India, and Bangladesh, before joining the Bay of Bengal. • The Lohit River is a vital tributary of the Brahmaputra, enhancing its geographical and hydrological significance. This makes the connection between the two rivers highly important. Related Concepts: • About the Lohit River: • The Lohit River originates from the Tibet Autonomous Region in China and enters India through Arunachal Pradesh. • It flows through the eastern parts of Arunachal Pradesh, passing through rugged terrain and picturesque valleys, making it an important geographical and cultural landmark. • The name "Lohit" means red river in Assamese, which reflects the reddish tinge of its waters due to the high iron content in the soil it flows through. • About the Brahmaputra River: • The Brahmaputra is one of the longest rivers in the world, with a length of about 2,900 kilometers. It originates in the Mansarovar region near Mount Kailash in Tibet, where it is called the Tsangpo. • The river flows through Tibet, India, and Bangladesh, covering a vast basin with a catchment area of approximately 580,000 square kilometers. • It is a transboundary river and plays a critical role in the agriculture, economy, and ecology of the regions it flows through. • Significance of Tributaries like Lohit: • Tributaries like the Lohit River contribute to the flow and sediment load of the Brahmaputra, making them crucial for the river's hydrology. • The water from tributaries supports agriculture, fisheries, and hydroelectric projects in the region, significantly impacting the local economy and livelihood. Important Notes: • Key Geographical Aspects: • The Brahmaputra River is one of the few rivers in the world with a male name, as most rivers have feminine names. • The river is known for its massive flooding during the monsoon season, which is caused by the heavy inflow of water from its tributaries, including the Lohit River. • Hydrological Importance: • The confluence of the Lohit River with the Brahmaputra enhances the river's flow and sedimentation, which is essential for maintaining the fertility of the plains in Assam and Bangladesh. • The river system supports a diverse range of flora and fauna, including endangered species like the Gangetic dolphin and the greater adjutant stork.