The correct answer is option 4, Lakshadweep. Lakshadweep is a group of islands located in the Arabian Sea. These islands are known for being made up of small coral atolls and reefs. Coral atolls are circular or oval-shaped islands that are formed from coral reefs that have grown on top of a volcanic island. Over time, as the volcanic island sinks and erodes, only the coral reef remains, forming a ring-shaped coral atoll. Reefs, on the other hand, are underwater structures made up of coral and other organic materials that provide a habitat for a diverse range of marine life. So, the islands in Lakshadweep are primarily made up of these coral atolls and reefs.

Option 1, Maldives, is incorrect because while the Maldives is also made up of small coral atolls and reefs, it is located in the Indian Ocean, not the Arabian Sea.

Option 2, Andaman, is incorrect because the Andaman Islands are primarily composed of volcanic origin and are not known for having coral atolls and reefs like the islands in the Arabian Sea.

Option 3, Sri Lanka, is incorrect because Sri Lanka is a large landmass with diverse geography and is not made up of small coral