There is no hard boundary between a coral reef and the open ocean. How does defining a boundary help scientists to better study a coral reef?

A.
Defining a coral reef boundary allows scientists to explain all ocean parts and interactions by studying the reef as a system.

B.
Defining a coral reef boundary allows scientists to focus on a smaller set of parts and interactions.

C.
Defining a coral reef boundary allows scientists to see how the parts of the reef interact with the parts of the rest of the ocean.

D.
Defining a coral reef boundary allows scientists to decide that the reef is not part of the ocean.