Which one of the following countries has the longest international boundary with India?

Correct option is A

India shares the longest international border with Bangladesh, stretching over approximately 4,096 km. This boundary covers five Indian states including West Bengal, Assam, Meghalaya, Tripura, and Mizoram. Explanation of options: (a) ✔ Bangladesh shares the longest boundary with India. (b) ✘ Bhutan shares a relatively small border with India. (c) ✘ China shares a significant but shorter border than Bangladesh. (d) ✘ Pakistan shares around 3,323 km, which is less than Bangladesh.