Which one of the following is not an international boundary line ?

The Dresden Line is not a recognized international boundary line. In contrast, the other options represent established historical or political borders. The Durand Line was established in 1893 as a boundary between Afghanistan and British India (now Pakistan) following a compromise between the British and Amir Abdur Rahman [3]. The Maginot Line was a famous French system of fortifications and defensive lines built during the interwar period to deter German invasion [1]. The 38th Parallel serves as the popular name for the latitude line that historically demarcated the boundary between North Korea and South Korea. While the context discusses various Indian boundaries like the McMahon Line [4] and the Radcliffe Award, it confirms the Durand Line's status as a formal demarcation [3]. There is no historical or geographical record of a 'Dresden Line' serving as an international border.

Sources

1. [3] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 16: India–Political Aspects > The Eastern Sector > p. 34
2. [1] Rajiv Ahir. A Brief History of Modern India (2019 ed.). SPECTRUM. > Chapter 5: Expansion and Consolidation of British Power in India > British India and the North-West Frontier > p. 132
3. [4] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 16: India–Political Aspects > Indo-Bangladesh Border > p. 43