Correct option is D
Sikkim, a small northeastern state of India, is uniquely positioned and shares international borders with three countries:
Nepal to the west
China (Tibet Autonomous Region) to the north and northeast
Bhutan to the east
It was the last state to join the Indian Union in 1975 through the 36th Constitutional Amendment.
• Sikkim is India’s second smallest state by population and area.
• Nathu La Pass, a historic trade route between India and Tibet, is located in Sikkim.
• The state capital is Gangtok.
• Kanchenjunga, India’s highest peak and the world’s third-highest mountain, lies in Sikkim.
• Sikkim is the first fully organic state of India.
• Tripura – Shares international borders with Bangladesh only.
• Assam – Shares borders with Bhutan and Bangladesh.
• Nagaland – Shares border with Myanmar.