A nurse is reviewing the laboratory data of a client following a hemodialysis treatment. The nurse should expect to find a decrease in which of the following laboratory values?

A. RBC count may be low in clients with kidney disease due to decreased erythropoietin, but it is not immediately affected by dialysis. B. Calcium levels may fluctuate but are generally managed with supplements and are not reliably decreased by dialysis. C. Potassium is effectively reduced by hemodialysis, which is a key goal in clients with hyperkalemia. D. Protein levels are not significantly affected by dialysis sessions, though protein loss can occur over time.