A client with chronic obstructive pulmonary disease (COPD) presented with shortness of breath. Oxygen therapy was started at 2 liters/minute via nasal cannula. The arterial blood gas (ABG) after the treatment was a pH of 7.36, PaCOÔéé 59 mm Hg, HCOÔéâÔü╗ 33 mEq/L, and a PaOÔéé 62 mm Hg. Which statement describes the most likely cause of the simultaneous increase in both the PaCOÔéé and the PaOÔéé?

B The hypoxic drive was reduced by the oxygen therapy. C The client had a pulmonary embolism that reduced perfusion. D The hypercapnia resulted from the rapid respirations. A The client had a pneumothorax which restricted ventilation.