The kidneys do not play a vital role in regulating:

The kidneys do not play a vital role in regulating blood glucose level. Hence, the kidneys play a vital role in ph balance, water balance and electrolyte balance which is called homeostasis refers to the maintenance of relative constancy or stability of the internal environment of the body. he urinary system play a key and central role in maintaining homeostasis in the body as a whole a nd because of metabolic activity occurring in every cell of the body and a host of both internal and external disturbances, you know as well that there are constant threats to both maintain and restoring that stability.

The answer is d. when it begins to fall back to the child's hand