Which Statement Exemplifies the Biological Pump Concept

Multiple Choice

Which statement exemplifies the biological pump concept?

A) Autotrophs bring in light photons to synthesize ATP.
B) Calcium ions are brought into cells while toxic physiological byproducts are released.
C) Bacteria oxidize Fe2+ into Fe3+, and Archaea reduce Fe3+ back into Fe2+.
D) Primary producers sink to the deep ocean, which provides deep ocean organisms with nutrients when the primary producers die.