The correct answer is option 1, Reunion island.
Volcanic islands are formed as a result of volcanic activity. Reunion island is a prime example of a volcanic island. It is located in the Indian Ocean and is an overseas department and region of France. The island is home to the Piton de la Fournaise, which is one of the most active volcanoes in the world.
Option 2, Andaman & Nicobar islands, is not of volcanic origin. These islands are a group of islands at the southeastern edge of the Bay of Bengal and are predominantly composed of coral reefs.
Option 3, Lakshadweep islands, is also not of volcanic origin. These islands are located off the southwestern coast of India and are mainly composed of coral reefs.
Option 4, Maldives, is not of volcanic origin either. The Maldives is a tropical paradise composed of a chain of coral islands.
In conclusion, out of the given options, only Reunion island is of volcanic origin and is known for its volcanic activity.