Which Statement Is NOT True About Living Coral Reefs

Multiple Choice

Which statement is NOT true about living coral reefs?

A) Coral reefs are generally restricted to water temperatures of 18°C or less.
B) Coral reefs are generally restricted to depths of 60 m below sea level.
C) The calcite reef skeleton is built by algae.
D) Algae provide oxygen that a key reef organism uses in order to secrete calcite.