Option 1 includes Bhutan, Bangladesh, and China as countries that share a border with Arunachal Pradesh. This is incorrect as Myanmar is not included in this option.
Option 2 includes Myanmar, Bangladesh, and China as countries that share a border with Arunachal Pradesh. This is incorrect as Bhutan is not included in this option.
Option 4 includes Bhutan, Bangladesh, and Myanmar as countries that share a border with Arunachal Pradesh. This is incorrect as China is not included in this option.
Option 3 is the correct answer. It includes Bhutan, China, and Myanmar as countries that share a border with Arunachal Pradesh. With these three countries, Arunachal Pradesh has a common border.