Which combination of arterial blood gas (ABG) values confirms respiratory acidosis if a male client with Guillain-Barré syndrome develops respiratory acidosis as a result of reduced alveolar ventilation?

A. pH, 5.0; PaCO2 30 mm Hg
B. pH, 7.40; PaCO2 35 mm Hg
C. pH, 7.35; PaCO2 40 mm Hg
D. pH, 7.25; PaCO2 50 mm Hg