Question: Coral reefs are found in shallow tropical ocean waters. A coral reef is a diverse ecosystem that is supported by the photosynthesis of marine plants and the algae that live within the tissues of the coral. Given this information, when would the waters in a coral reef likely have the highest dissolved oxygen concentration?

  Options: 
 A. 7 a.m.
 B. 2 p.m.
 C. 9 p.m.
 D. midnight
Answer: B