This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics, Subject name: Medicine
Cystic fibrosis affects all systems EXCEPT: 
Select and explain. 
A. Respiratory, B. Endocrine, C. Hepatobiliary, D. Genitourinary
B: Endocrine
Answer: B: Endocrine 
Explanation: ANSWER: (B) EndocrineREF: Harrison's Internal Medicine, Chapter 253, Davidson's internal medicine 20tSl edition page- 685FEATURES OF CYSTIC FIBROSIS:A- Autosomal recessiveB- BronchiectasisC- Chloride channel block/Ciliary dysfunctionD- Diabetes mellitusE- Exocrine pancreatic failure (>90% of patients with CF)F- Fat malabsorption (steatorrhoea)G- Gall stone/Gene mutation on chromosome 7H- Hepatic cirrhosis/HemoptysisI- Intestinal obstruction/Infertility