Following is true about cystic Fibrosis: (A) Nasal polyposis is absent, (B) Sweat chloride levels > 30 mmol / L is diagnostic, (C) Staphylococcus is most common pathogen  causing  infection in cystic fibrosis in adults., (D) Chromosome - 7 genetic defect
Answer is D. In adults pseudomonas is most common arganism causing infection in cystic fibrosis adult patients.
Sweat chloride levels > 60 mmol / L is diagnostic.
Nasal polyps is present.