What Role Do Chloride Cells Play in Osmoregulation of Marine

What role do chloride cells play in osmoregulation of marine fish with bony skeletons?

A) They actively transport chloride into the gills.
B) They mediate the movement of salt from seawater through their gills.
C) They are involved in excretion of excess salt.
D) They actively transport salt across the basolateral membrane of the rectal gland.