as adults, almost all reef-building corals are sessile. this means that the reef-building corals are emergents or succulents

Question

A. Are emergent B. Are succulents C. Stay in one place D. Feed on the ocean floor

Answer 1

Coral reefs are succulents, remain attached to their substratum and feed on the limited nutrients from their marine environment/biome.

 

You can find out more bout them at NOAA's web site detailing  coral reef conservation program.