The answer is D. Coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps belong to a group of animals known as Cnidaria, which also includes sea anemones and jellyfish. Unlike sea anemones, corals secrete hard carbonate exoskeletons which support and protect the coral polyps. Most reefs grow best in warm, shallow, clear, sunny and agitated water. @wiki Hope this helps and if your feeling generous give it a rate, thanks and brainliest because it would really help me get virtuoso and I would appreciate it ;)
Answer: d. It is composed of thousands of individual coral organisms.
Explanation: Coral are marine invertebrate organisms which belong to the phylum Cnidaria. Coral polyps are the organisms which are identical to each other and they remain in the colonies. The corals species forms the reef typically in the tropical oceans by secreting calcium carbonate to form hard skeleton. This reef helps the animals to remain protected against the predators and they also provide a shelter to a number of marine animals.
On the basis of the above information, d. It is composed of thousands of individual coral organisms. is the correct option.
