Why does the author provide the information that "phytoplankton populations rise and fall much more quickly than nutrient concentrations change"? A. To argue that the nutrient level not determine phytoplankton succession. B. To argue that the succession of phytoplankton is actually the cause of changes in the nutrient level. C. To indicate that phytoplankton populations are very sensitive to changes in the nutrient level. D. To imply that changes in the nutrient level explain the succession of phytoplankton.