A. Erythropoietin is incorrect because it primarily stimulates red blood cell production in the bone marrow in response to hypoxia. It does not play a role in sodium reabsorption or water balance. B. Aldosterone is correct because it is a mineralocorticoid hormone released from the adrenal cortex that increases sodium reabsorption in the distal tubules and collecting ducts of the kidneys. As sodium is reabsorbed, water follows by osmosis, leading to increased water retention, increased blood volume, and increased blood pressure. C. Calcitonin is incorrect because it is involved in calcium regulation. It lowers blood calcium levels by inhibiting bone resorption and increasing calcium excretion by the kidneys. It does not affect sodium or water retention. D. Antidiuretic hormone (ADH) is incorrect because although it does promote water reabsorption in the kidneys, it does so by increasing the permeability of the collecting ducts to water, not by increasing sodium reabsorption. Therefore, it causes water retention independently of sodium.