Biogeochemical cycles on Earth serve a variety of different purposes. What do the biogeochemical cycles have in common?

a.
They all serve the same function in sustaining life on Earth.
b.
They all include only nonliving components of an ecosystem.
c.
They are all essential for sustaining life on Earth.
d.
They all include only living components of an ecosystem.

Please select the best answer from the choices provided

A
B
C
D