The correct option is "1 only." Barren Island is indeed an active volcano situated in Indian territory, specifically in the Andaman and Nicobar Islands. However, statement 2 is incorrect as Barren Island is approximately 138 km northeast of Port Blair, and statement 3 is also inaccurate because the volcano erupted in 2017, meaning it has not remained inactive since 1991. This question underscores the need for precise geographical knowledge and understanding of volcanic activity, which is crucial for civil services examination preparation.