Question

Atolls are geological formations made up of :

Answer 1

The correct answer B. Coral.

Explanation

An atoll is a geological formation that is an island of coral origin that forms in the ocean. Atolls are generally ring-shaped. These islands are formed when reefs formed around a volcanic island once it sinks into the ocean. Many of the atolls on earth are in the Pacific Ocean area. According to the above, the correct answer is B. Coral.