Which of the following Indian states shares a border with Bhutan?

4) Assam, West Bengal, Sikkim, Arunachal Pradesh Key Points India shares a 699 km long international border with the Kingdom of Bhutan, which is a landlocked country in the Eastern Himalayas. Four Indian states share their borders with Bhutan: Assam (267 km), Arunachal Pradesh (217 km), West Bengal (183 km), and Sikkim (32 km). Assam shares the longest stretch of the border with Bhutan , while Sikkim shares the shortest. The border is unique because it is an open border , allowing citizens of both countries to cross without a visa or passport, reflecting the deep-rooted diplomatic and cultural relationship between India and Bhutan. The border is managed and protected by the Sashastra Seema Bal (SSB) , an elite central armed police force of India. The diplomatic relations between the two nations are governed by the Indo-Bhutan Treaty of Peace and Friendship , originally signed in 1949 and updated in 2007 to reflect contemporary realities. Geographically, the border marks the transition from the fertile plains of the Dooars in India to the steep, rugged mountains of the Bhutanese Himalayas. The border is vital for trade and commerce, with major transit points like Phuntsholing (Bhutan) and Jaigaon (India) serving as critical economic gateways. Additional Information Option 1 (Assam, Manipur, Mizoram, Nagaland): While Assam borders Bhutan, the states of Manipur, Mizoram, and Nagaland share their international borders with Myanmar . The India-Myanmar border is approximately 1,643 km long and is characterized by the Free Movement Regime (FMR) which allows tribes living along the border to travel 16 km across either side without a visa. Option 2 (Punjab, Rajasthan, Gujarat, Ladakh): These regions share their international borders with Pakistan . The India-Pakistan border, which includes the Radcliffe Line and the Line of Control (LoC), is one of the most heavily militarized borders in the world. Ladakh also shares a border with China (Line of Actual Control). Option 3 (West Bengal, Bihar, Uttar Pradesh, Uttarakhand): These states share their international borders with Nepal . Similar to the Bhutan border, the India-Nepal border is also an open border that facilitates extensive socio-economic interactions between the people of the two nations. West Bengal is the only state mentioned in this option that borders multiple countries (Nepal, Bhutan, and Bangladesh). Bordering Countries of India: India shares land borders with seven countries: Bangladesh, China, Pakistan, Nepal, Myanmar, Bhutan, and Afghanistan . The longest land border is with Bangladesh (4,096.7 km), while the shortest is with Afghanistan (approx. 106 km in the POK region). Strategic Significance of Bhutan: Bhutan acts as a buffer state between India and China. The security of the "Siliguri Corridor" (Chicken's Neck), which connects mainland India to the Northeast, is closely linked to India's strategic partnership with Bhutan, especially in areas like the Doklam plateau.