Option 1: China -> India-China border is approximately 3,488 km long.
Option 2: Bangladesh -> India-Bangladesh border is approximately 4,096 km long, making it the longest.
Option 3: Pakistan -> India-Pakistan border is approximately 3,323 km long.
Option 4: Nepal -> India-Nepal border is approximately 1,751 km long.
Hence, Option 2: Bangladesh -> The India-Bangladesh border at approximately 4,096 km is the longest land border India shares with any neighboring country, spanning across five Indian states (West Bengal, Assam, Meghalaya, Tripura, and Mizoram) -> correct