Answer to Question 1
Fringing reefs cling to margins. They are common in areas that have low rainfall runoff, mainly leeward sides of tropical islands. Salinity and water clarity are dependable in these reefs. Fringe reefs establish on new tropical islands.
Barrier reefs separated from land by a lagoon. These reefs occur at lower latitudes than fringe reefs. They are parallel to continental shores. The seaward side grows rapidly due to an abundance of food. The lagoon side is much slower to grow because there is a great deal of sediment and freshwater and a lack of nutrients.
An atoll is a ring-shaped island of coral reef. There is an enclosed or nearly enclosed lagoon in the center. There is no land protruding at an atoll. The central lagoon connects to the deep water outside via channels. The corals are not able to thrive within the lagoon.
Answer to Question 2
C