A nurse at an emergency department is caring for a child who was admitted with cystic fibrosis. The child's parent is given the following laboratory results: sodium 128 mg/dL (136 to 145 mEq/dL), blood glucose 268 g/dL (70 to 100 g/dL) potassium 4.2 mg/L (3.4 to 4.7 mEq/L), and oxygen saturation 88% on 2 L/min via nasal canula (95% to 100%). The parent ask how the values relate to cystic fibrosis. Which of the following statements by the nurse is accurate?

Rationale: A. Cystic fibrosis affects the CFTR protein, which regulates sodium and chloride transport across epithelial cells. This dysfunction leads to abnormal salt (sodium) loss in sweat and contributes to hyponatremia, as seen in this child. B. Oxygen saturation decreases—not increases—due to impaired gas exchange caused by thick mucus and lung damage. C. Although CF can affect pancreatic function (leading to diabetes over time), the intestines are not the primary reason for elevated blood glucose in CF. D. Potassium levels are generally not directly affected by mucus production in the lungs.