Answer:
The correct answer is A. coral
Step-by-step explanation:
Corals are animals belongs to the phylum Cnidaria. Corals live in colony. Each individual coral is called polyp. Each polyp has a simple body with single opening is mouth surrounded by tentacles which are stinging organ. Corals are sessile and are permanently attached to the floor of the water bodies such as streams. They are free-living and within the most of the coral tissues contain microscopic algae zooxanthellae. These photosynthetic algae produce food and oxygen for the corals using their metabolic waste.