The correct answer to the question: When the pH of the extracellular fluid drops, the kidneys:____, would be: C: excrete fewer bicarbonate ions.
The pH of the human body, given by the extracellular fluid that flows and is contained in it, holds a narrow margin between 7.35 and 7.45. When hydrogens ions increase, and bicarbonate ions decrease, in any of these fluids, be it blood, CSF, or any other, then we known that a person´s body is going into acidosis because the pH level is dropping. However, when the scenario is the opposite, with more bicarbonate ions, than hydrogen ions, then we are talking of an alkalosis. In order for the body to restore its normal levels, it has a series of mechanisms that will ensure the reestablishment of balance. One such mechanism is the excretion of elements through the urine, by the kidneys. In a case of acidosis then, the correct procedure is that kidneys produce urine charged with the excess hydrogen atoms and re-uptakes bicarbonate ions that might have escaped while producing urine. The urine will become acidic then. This is why the answer is C.