Choice A rationale:

Increased lung compliance is not a common respiratory complication of cystic fibrosis (CF).

CF is characterized by the production of thick and sticky mucus in the airways, which leads to decreased lung compliance.

This thick mucus obstructs the airways, making it difficult for the child to breathe.

Choice B rationale:

Decreased breath sounds are a common respiratory complication of CF.

The thick and sticky mucus produced in CF can block the airways, leading to decreased breath sounds upon auscultation.

This can result in impaired air movement and reduced ventilation in affected areas of the lungs.

Choice C rationale:

Normal oxygen saturation is not typically a common respiratory complication of CF.

CF often leads to decreased oxygen saturation due to the impaired lung function caused by mucus buildup and recurrent infections.

Choice D rationale:

Clear and thin sputum production is not a common finding in CF.

CF is associated with the production of thick and sticky mucus, leading to productive cough with thick, tenacious sputum.