A 10-year-old child presents with recurrent chest infections, pancreatic insufficiency, and failure to thrive. A sweat test shows elevated chloride levels. What is the underlying pathophysiology?AExcess chloride reabsorption in sweat glandsBDefective chloride channels (CFTR) in epithelial cellsCOverproduction of mucus by hypertrophic goblet cellsDPrimary immunodeficiency affecting lung defencesEAutoimmune destruction of pancreatic acinar cellsCheck my answer