Cigarette Smoking Can Sometimes Lead to Development of a "Smoker's

Cigarette smoking can sometimes lead to development of a "smoker's cough," which results from paralysis of cilia in the airways. Why would the paralysis of cilia lead to smoker's cough?

A) Paralyzed cilia can no longer clear the airways of mucus, so coughing helps remove it.
B) Paralyzed cilia can no longer provide an immune response to protect the airways from harmful compounds in the smoke, so coughing is used to try to prevent the compounds from damaging the airways.
C) Paralyzed cilia lead to a nervous response that "tickles" the airways and induces coughing.
D) Paralyzed cilia push mucus downward into the alveoli, which coughing attempts to remove.