Aryan, a 14-year-old boy presented with chronic diarrhea and weight loss. History reveals thathe has repeated attacks of respiratory tract infections with Pseudomonas aeruginosa. His younger brother died from a severe respiratory infection at the age of 7. Which of the following agents is most likely to improve this patient's condition?

(Ref: Katzung 11/e p1093) In a young male, a history of recurrent respiratory infections with P. aeruginosa, chronic diarrhea, weight loss, and death of a sibling due to respiratory infection suggests a diagnosis of cystic fibrosis (CF). Chronic diarrhea and weight loss in patients with CF are typically caused by malabsorption secondary to pancreatic insufficiency and can be correced by pancreatic enzyme supplementation.