In Ecosystems,why Is the Term Cycling Used to Describe the Transfer

Multiple Choice

In ecosystems,why is the term cycling used to describe the transfer of chemical elements,whereas the term flow is used for energy exchange?

A) Chemical elements are repeatedly used,but energy passes through and between ecosystems.
B) Photosynthesis results in transforming chemical elements with no effect on energy transfer.
C) Chemical elements flow between ecosystems,whereas energy stays within one ecosystem.
D) Photosynthesis alters system energy without a change in the number of chemical elements.