The given question asks us to identify a state based on certain characteristics. Let`s analyze each option to understand which state could be the correct answer.

Option 1: Tripura - Tropic of Cancer passes through Tripura, so the first characteristic is matched. However, Tripura does not have an international border with Bangladesh and Myanmar, so this option can be ruled out.

Option 2: Mizoram - Tropic of Cancer passes through Mizoram, fulfilling the first characteristic. Mizoram also has a significant north-south extension, fulfilling the second characteristic. Moreover, Mizoram shares an international border with both Bangladesh and Myanmar, satisfying the third characteristic. Therefore, this option matches all the given characteristics and is a strong contender for the correct answer.

Option 3: Nagaland - Nagaland does not have the Tropic of Cancer passing through it, so it does not fulfill the first characteristic and can be ruled out.

Option 4: Manipur - Manipur does not have the Tropic of Cancer passing through it, so it does not fulfill the first characteristic and can be ruled out.

Based on the analysis of each option, option 2, Mizoram, seems to be the correct answer as it matches all the given characteristics.