Which one of the following islands is of volcanic origin ?

Réunion Island is a classic example of a volcanic island formed by a mantle plume or hotspot in the Indian Ocean [2]. It is entirely volcanic, originating from the ocean floor at a depth of 4,000 meters and is composed of two major shield volcanoes: the extinct Piton des Neiges and the highly active Piton de la Fournaise [4]. In contrast, the Lakshadweep and Maldives are coral atolls resting on submerged volcanic structures [3]. While the Andaman and Nicobar Islands have some volcanic elements, such as Barren Island, they are primarily tectonic in origin, formed by the collision between the Indian and Burma plates [3]. Therefore, Réunion is the most distinctively volcanic island among the options, as its entire landmass is built from basaltic lava flows [1].

Sources

1. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 12: Hotspot Volcanism > Reunion Hotspot > p. 165
2. [1] https://www.usgs.gov/news/volcano-watch-reunion-island-sister-island-other-side-world
3. [4] https://www.sciencedirect.com/science/article/pii/037702738990005X
4. [3] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 2: Physiography > THE INDIAN ISLANDS > p. 66