The McMahon Line is a 2,400-kilometre (1,500 mi) border between India and China (Tibet). It was drawn in 1914 by the British government and the Tibetan government, but China has never accepted it. The McMahon Line runs from the tripoint with Burma in the east to the tripoint with Nepal in the west. It passes through the Indian states of Arunachal Pradesh, Assam, and Sikkim.
The McMahon Line was drawn in an attempt to resolve the border dispute between India and Tibet. The British government wanted to ensure that India had a secure border with Tibet, and the Tibetan government wanted to ensure that it had access to the Indian markets. The McMahon Line was drawn in accordance with the Simla Convention of 1914, which was signed by the British government, the Tibetan government, and the Chinese government. However, the Chinese government never ratified the Simla Convention, and it has never accepted the McMahon Line.
The McMahon Line has been a source of tension between India and China for many years. In 1962, China invaded India and captured some territory that is claimed by India. The two countries have since agreed to maintain the status quo along the McMahon Line, but the border dispute remains unresolved.
Option a is the correct answer. The McMahon Line demarcated the border between India and China (Tibet). Option b is incorrect because the McMahon Line does not demarcate the border between India and Bhutan. Option c is incorrect because the McMahon Line does not demarcate the border between India and Burma (Myanmar). Option d is incorrect because the McMahon Line does not demarcate the border between Assam and Arunachal Pradesh.