The Indo-Bangladesh border - which is 4096.70 km long runs along the states of: _______.
1
Sikkim, West Bengal, Assam and Arunachal Pradesh
2
Manipur, Mizoram, Nagaland and Arunachal Pradesh
3
West Bengal, Assam, Meghalaya, Tripura and Mizoram
4
Uttarakhand, Uttar Pradesh, Bihar, West Bengal and Sikkim