Explanation:

1.Arunachal Pradesh shares its international border with Bhutan in the west, China in the north and the north-east, and Myanmar in the east.

2.Assam shares an international border with Bhutan and Bangladesh.

3.Mizoram shares international borders with Bangladesh and Myanmar.

4.Tripura shares its international border only with Bangladesh.

So, Arunachal Pradesh, Assam, and Mizoram share international borders with two or more countries. In contrast, Tripura shares its international border with only one country.

Hence, three out of the four mentioned states share international borders with two or more countries.