Nepal is the answer that matches the Bihar-specific fact asked in the question. Bihar shares its international border with Nepal to the north. The border between Bihar and Nepal spans approximately 729 km. This northern border runs along the districts of West Champaran, East Champaran, Sitamarhi, Madhubani, Supaul, Araria, and Kishanganj. The border is significant as it facilitates trade, cultural exchange, and movement of people between the two countries. China shares its border with Tibet and Indian states like Sikkim and Arunachal Pradesh, not Bihar. Bangladesh shares its border with West Bengal and northeastern states, not Bihar. Bhutan shares its border with Assam, Arunachal Pradesh, Sikkim, and West Bengal, not Bihar. The Nepal border is also important from a security perspective and is monitored by the Sashastra Seema Bal (SSB). This geographical fact is a standard question in BPSC and Bihar General Studies examinations. Bihar GK questions frequently place neighbouring districts, rivers, historical centres, personalities or government institutions together as distractors, so recognition of a familiar name alone is insufficient. The alternatives China, Bangladesh, Bhutan may be valid Bihar-related terms, but they do not satisfy the complete relationship asked here. Revise the complete pair ‘Bihar shares its border with which neighboring country? — Nepal’ rather than an isolated option letter. This approach improves accuracy in BPSC, Bihar Police, teacher recruitment, SSC, Railway and other examinations while reducing confusion between closely related state facts..
