The correct answer is Assam. In News • On February 14, 2026, the Union Cabinet chaired by Prime Minister Narendra Modi approved India’s first underwater road-rail tunnel project in Assam. Explanation & Key Takeaways: • The Project: The tunnel will be constructed under the Brahmaputra River, connecting Gohpur and Numaligarh in Assam. • Strategic Connectivity: This is a first-of-its-kind project in India that integrates both road and rail networks within a single underwater tunnel system. • Defense Importance: The project is of immense strategic significance as it will provide year-round connectivity between the north and south banks of the Brahmaputra, facilitating the rapid movement of troops and supplies toward the Arunachal Pradesh border. • Technical Marvel: The tunnel is designed to be approximately 15 kilometers long and will bypass the need for traditional bridges that are often vulnerable to seasonal flooding. • Economic Impact: It will drastically reduce travel time between key regions of Upper Assam and boost trade and commerce in the Northeast. Related Concepts: • Brahmaputra River • One of the largest rivers in the world, it is prone to heavy siltation and flooding, making underwater tunneling a complex but stable alternative to surface bridges. • Numaligarh Refinery • The tunnel will also benefit major industrial hubs like the Numaligarh Refinery by streamlining logistics and transport routes.