Which of the following statement relating to cystic fibrosis is/are correct?

b. Cystic fibrosis is caused by a defective chloride channel

d. Cystic fibrosis is inherited as an autosomal recessive trait

Cystic fibrosis is a lethal autosomal recessive disorder caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR gene encodes a 170 kDa protein that functions as a cAMP-regulated chloride-channel on the apical surface of epithelial cells.