A ring-shaped coral reef or chain of coral islands that encloses a lagoon in its centre is called:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → An atoll
Coral polyps build reefs in warm, shallow tropical seas. When a reef grows as a ring round a central lagoon, it is called an atoll. Many islands of Lakshadweep and the Maldives are atolls.