Which of the following countries does the North-East region share its boundaries with?

The correct option is China, Myanmar and Bangladesh.

To understand why this is the correct answer, let us look at the geographical boundaries of the North-East region of India step-by-step:

1. Northern Boundary:
The North-East region of India (comprising states like Arunachal Pradesh and Sikkim) shares its northern border with China (specifically the Tibet Autonomous Region).

2. Eastern Boundary:
On the eastern front, the states of Arunachal Pradesh, Nagaland, Manipur, and Mizoram share a long international border with Myanmar (Burma).

3. Southern and Western Boundary:
In the south and west, the states of Tripura, Meghalaya, Mizoram, Assam, and West Bengal (which connects the region to the rest of India) surround and share a border with Bangladesh.

Why other options are incorrect:
- Nepal shares boundaries with Uttarakhand, Uttar Pradesh, Bihar, West Bengal, and Sikkim, but it is not a primary boundary partner for the main North-East region cluster compared to Myanmar.
- Bhutan is indeed bordered by Sikkim, West Bengal, Assam, and Arunachal Pradesh, but the option "China, Bhutan and Bangladesh" excludes Myanmar, which shares a massive border along the entire eastern edge of the North-East states.
- Sri Lanka is an island nation located off the southern coast of India and does not share any land boundary with India, let alone the North-East region.

Therefore, the group of countries that the North-East region shares its international boundaries with is China, Myanmar and Bangladesh.