This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cystic fibrosis & Sleep apnea, Subject name: Medicine
Which of the following is not true about cystic fibrosis? 
Select and explain. 
A. The defective gene encodes for the membrane protein called cystic fibrosis trans membrane channel regulator, B. Normal CFTR is an ion channel specific for calcium, C. Autosomal recessive, D. Altered pH of the surface secretions decreases bactericidal activity.
B: Normal CFTR is an ion channel specific for calcium
Answer: B: Normal CFTR is an ion channel specific for calcium 
Explanation: Cystic fibrosis transmembrane conductance regulator (CFTR) is a membrane protein and chloride channel in veebrates that is encoded by the CFTR gene. The CFTR gene codes for an ABC transpoer-class ion channel protein that conducts chloride ions across epithelial cell membranes.