Which among the following states of India does not share its border with Bhutan?

Option 1: Sikkim -> Shares its border with Bhutan in the north and northeast.

Option 2: West Bengal -> Shares its border with Bhutan in the Alipurduar and Jalpaiguri districts.

Option 3: Tripura -> Located in Northeast India but surrounded by Bangladesh on three sides; does not border Bhutan.

Option 4: Arunachal Pradesh -> Shares its longest border with Bhutan in the west.

Hence, Option 3: Tripura -> Four Indian states share their borders with Bhutan: Sikkim, West Bengal, Assam, and Arunachal Pradesh. Tripura, despite being in Northeast India, is geographically separated from Bhutan and shares borders only with Bangladesh, Assam, and Mizoram -> correct