Step 1: Understanding the Concept:
Geography and geology identify unique physical features across regions, including active tectonic and volcanic sites.
Step 2: Detailed Explation:
The Andaman and Nicobar Islands, located in the Bay of Bengal, are part of an island arc formed by tectonic subduction along the boundary between the Indo-Australian and Eurasian plates.
Barren Island is located in the Andaman Sea, approximately \(135 \text{ km}\) northeast of Port Blair.
It is the only confirmed active volcano in India and along the entire active volcanic chain from Sumatra to Myanmar.
Its first recorded eruption occurred in 1787, and it has erupted several times since, with recent activity recorded in 2017 and subsequent years.
The other options do not refer to active volcanoes within Indian territory:
• Sumatra is an island in Indonesia.
• Lahars is a geological term for a volcanic mudflow.
• Mya is not an active Indian volcanic island.
Thus, Barren Island is the correct answer.
Step 3: Fil Answer:
The correct option is (A).