Solution

The McMahon Line is a border demarcation line between India and China in the eastern sector of the India-China border. It separates the Indian state of Arunachal Pradesh (formerly known as the North-East Frontier Agency) and the Chinese-administered Tibet Autonomous Region. Therefore, India and Bhutan are the countries that share a border with China along the McMahon Line. The other options (Nepal, Myanmar, Laos, and Bangladesh) do not share a border with China along the McMahon Line.