Which statement accurately describes the flow of energy in an ecosystem that lacks oxygen? Choose 1
Choose 1

(Choice A)
A
After energy enters the ecosystem via photosynthesis, energy flow stops, because all other major metabolic processes require oxygen.

(Choice B)
B
Energy flow occurs as organisms carry out anaerobic respiration, which does not require oxygen.

(Choice C)
C
Energy flow occurs as organisms use aerobic cellular respiration, which requires only carbon dioxide.