Which Indian state shares the longest land border with Bhutan?

The correct answer is option 4) i.e. Four. The Bhutan–India border is the international border separating Bhutan and India. The border is 699 km long, and adjoins the Indian states of Assam (267 km), Arunachal Pradesh (217 km), West Bengal (183 km), and Sikkim(32 km). India has 15,106.7 Km of land border and a coastline of 7,516.6 Km including island territories. The length of our land borders with neighbouring countries is as under: Bangladesh - 4096.7, China - 3488, Pakistan - 3323, Nepal - 1751, Myanmar -1643, Bhutan - 699, Afghanistan -106.