A Patient with a Measured Plasma HCO₃^- Concentration of 24

A patient with a measured plasma HCO₃^- concentration of 24 mmol/L has an episode of acute hypoventilation, with the PCO₂ rising from 40 to 70 mm Hg. What do you predict will happen acutely to the plasma HCO₃^- concentration?

A) HCO₃^- will remain unchanged.
B) HCO₃^- will rise to approximately 27 to 28 mmol/L.
C) HCO₃^- will fall to approximately 20 to 21 mmol/L.
D) HCO₃^- will rise to approximately 54 to 55 mmol/L.