Which one of the following states of India is surrounded by Bangladesh on three sides ?

The Indian state of Tripura is surrounded by Bangladesh on three sides: the north, south, and west [t1][t2]. Tripura shares a significant international border of approximately 856 kilometers with Bangladesh, which accounts for about 84% of its total border length [t2][t3][t5]. Geographically, the state is located in the northeastern part of India and is connected to the rest of the country only through the states of Assam and Mizoram on its eastern side [t1][t3]. While other Indian states like West Bengal, Meghalaya, Mizoram, and Assam also share borders with Bangladesh, none are enclosed on three sides by the neighboring country [t5][t8]. West Bengal shares the longest total border with Bangladesh (2,216.7 km), but it is primarily located to the west of Bangladesh rather than being surrounded by it [t5].