Which one among the following is not a coral reef island?

Coral reef islands are landforms primarily composed of coral debris and organic matter, categorized into fringing reefs, barrier reefs, and atolls [3]. The Great Barrier Reef in Australia is the world's largest barrier reef system [3]. Rainbow Reef, located near Taveuni in Fiji, is a renowned coral reef structure. Swaraj Island (formerly Havelock Island) in the Andaman and Nicobar archipelago is characterized by fringing coral reefs [3]. In contrast, Kyushu is one of the four main islands of Japan and is primarily a volcanic and tectonic landmass rather than a coral reef island. While Japan has coral reefs in its southern Ryukyu chain, Kyushu itself is dominated by mountainous volcanic terrain, including active volcanoes like Mount Aso. Therefore, Kyushu does not fit the definition of a coral reef island formed by the accumulation of calcium carbonate from coral polyps [3].

Sources

1. [1] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 11: Islands and Coral Reefs > Types of Goral Reef > p. 100
2. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 17: Major Landforms and Cycle of Erosion > Coral Reef Relief Features > p. 220
3. [3] CONTEMPORARY INDIA-I ,Geography, Class IX . NCERT(Revised ed 2025) > Chapter 2: Physical Features of India > Corals > p. 14