A nurse is reviewing the arterial blood gas values of a client who has chronic kidney disease. Which of the following sets of values should the nurse expect?

pH 7.55, HCO3- 30 mEq/L, PaCO2 31 mm Hg.

pH 7.30, HCO3- 26 mEq/L, PaCO2 50 mm Hg.

pH 7.50, HCO3- 20 mEq/L, PaCO2 32 mm Hg.

pH 7.25, HCO3- 19 mEq/L, PaCO2 30 mm Hg.