The correct option is Eastern margin.
Explanation
The Indian Plate is a tectonic plate that interacts with surrounding plates through convergent, divergent, and transform boundaries. Its margins are defined by distinct geological features such as mountain ranges, oceanic ridges, and trenches.
Boundary Analysis
- Northern Boundary: Marked by the Himalayas, representing a continent-continent convergent boundary where the Indian Plate collides with the Eurasian Plate.
- Western Margin: Follows the Kirthar Mountain range (Pakistan) and the Makran coast. It continues southeastward along the Chagos Archipelago as a spreading site.
- Southern Boundary: Marked by a mid-oceanic ridge (divergent boundary) separating the Indian Plate from the Antarctic Plate.
- Eastern Margin: This boundary extends through the Rakine Yoma Mountains of Myanmar towards the island arc along the Java Trench (also known as the Sunda Trench). This is a convergent boundary where the oceanic crust of the Indian Plate subducts beneath the Burma Plate (part of the Eurasian system).
Key Takeaway: The Java Trench marks the eastern margin of the Indian Plate, forming a continuous subduction zone that connects with the Arakan Yoma range in Myanmar.