Answer: c. bicarbonate ions
Step-by-step explanation:
The carbonic acid-bicarbonate ion buffer system works with the Le Chateiler’s Principle.
The bicarbonate and carbonic acid are always in equilibrium in the blood. The low pH is coupled with the release of bicarbonate ion into the blood plasma, where it neutralizes the high H+ concentration of the blood by forming carbonic acid.(H2C03). Increasing the pH, thereby normalising it
H3 0+ + H2C03 ⇄ H2C03 + H 20,
This is a weak acid which dissociated into H+ and H2C03.. The hydrogen ion is mopped by the hemoglobin,( therefore stabilizing the pH while the carbonic anion( HC03-) is transported to the lungs where it is broken down for the C02 to be exhaled in the lungs.