The secretory coil fills the lumen with a NaCl solution that is isotonic with the blood plasma. As this solution moves upward through the reabsorptive duct, NaCl is reabsorbed into the blood, such that the sweat that is secreted onto the skin surface is hypotonic. Suppose that along its entire length, the walls of the sweat gland consist of a single layer of epithelial cells joined by tight junctions. Which one of the following statements about this system is false?

a.

One would not expect to find aquaporin channels in the membranes of reabsorptive epithelial cells.

b.

One would expect intracellular [Na+] to be lower than extracellular [Na+] in both the secretory and reabsorptive epithelial cells.

c.

CFTR Cl- channels are located in the apical membranes of secretory epithelial cells.

d.

In reabsorptive epithelial cells, one would expect to find Na+/K+ pumps only in the apical membrane.