Hello! Your answer would be B, the kidneys are paired organs that regulate water and electrolyte balance in terrestrial vertebrates.
The kidneys are paired organs (eliminating option C) which function as the body's filter for blood. They extract wastes and extra fluid. This creates urine (eliminating option D).
In the final two choices, option A and option B, option B is the correct one. For option a, blood glucose is regulated by hormones. Therefore, option B is correct.
Hope this helps!