Answer:
The correct answer is b cystic fibrosis .
Explanation:
Cystic fibrosis is a genetic disorder.It occur due to mutation in a protein called cystic fibrosis trans membrane conductance regulator or simply CFTR.
CFTR is a integral membrane protein that helps in the transport of chloride ions(Cl-).
The production of sweat ,mucus occur due to the proper functioning of CFTR.If CFTR become nonfunctional due to mutation the secretion becomes thick and this thick secretion accumulate in lungs to cause respiratory tract infection.
Beside lungs cystic fibrosis also affect other organs such as pancreas,kidney etc.
