India has its longest international land border with which neighbouring country?

Introduction / Context:
Borders and neighbours are a very important part of Indian geography. Knowing which country shares the longest land boundary with India helps you understand political relations, trade routes and security issues. This question tests your ability to recall the approximate length and relative ranking of India's land borders with its neighbours such as Bangladesh, Pakistan, Nepal, Bhutan and Myanmar.

Given Data / Assumptions:

- The question states that India has its longest international border with one particular neighbouring country.

- Options include Bhutan, Nepal, Bangladesh, Pakistan and Myanmar, which all share land boundaries with India.

- The question does not need exact kilometre values, only a comparison to identify which border is the longest.

- It assumes standard political boundaries as understood in school level geography.

Concept / Approach:
India shares land borders with Pakistan, Afghanistan (very small), China, Nepal, Bhutan, Myanmar and Bangladesh. Among these, the India Bangladesh border is the longest, stretching over the eastern part of the country and wrapping around Bangladesh on several sides. The India Pakistan border is also long but still shorter than the India Bangladesh boundary. Borders with Nepal, Bhutan and Myanmar are comparatively shorter. Therefore, the correct approach is to recall the relative order: Bangladesh has the longest land border with India, followed by China and Pakistan, and then by other neighbours.

Step-by-Step Solution:
Step 1: List the neighbours that share land borders with India: Pakistan, China, Nepal, Bhutan, Bangladesh, Myanmar and a very small boundary with Afghanistan. Step 2: Recall approximate lengths. India Bangladesh is often quoted as more than 4000 kilometres of border, making it the longest. Step 3: Remember that the India Pakistan border, while significant, is shorter than the India Bangladesh border. Step 4: Understand that Nepal and Myanmar have moderate length borders, and Bhutan has an even smaller boundary with India. Step 5: Compare these lengths and see that Bangladesh clearly stands out as the neighbour with the longest land boundary with India. Step 6: Select Bangladesh as the correct answer, since no other option matches this description.

Verification / Alternative Check:
You can cross check by remembering standard exam facts. Many geography and general studies books highlight that the India Bangladesh border is the longest international border that India shares with any country. They often mention that this border is highly irregular, with enclaves and riverine segments, which increases its total length. The India Pakistan border is always presented as important but second in length. Recalling these repeated facts from your notes confirms that Bangladesh is the correct option for this question.

Why Other Options Are Wrong:
Bhutan shares only a relatively short part of India's northern border and is much smaller in area than Bangladesh. Nepal has a longer border than Bhutan but still significantly shorter than the India Bangladesh boundary. Pakistan does share a major border with India, but it is shorter than the border with Bangladesh. Myanmar touches India in the northeast but its boundary length with India is also less than that of Bangladesh.

Common Pitfalls:
Students sometimes pick Pakistan because of frequent news coverage of that border, associating importance with length. Others may be misled by China, which is not even present as an option in this question. To avoid confusion, always remember a simple fixed fact for exams: India has its longest land boundary with Bangladesh. Fixing this one line in memory will help you answer many similar questions quickly and confidently.

Final Answer:
India has its longest international land border with Bangladesh.