Final answer:
Cough-suppressant medications would be least likely to be used for a child with cystic fibrosis who is hospitalized with a respiratory infection.
Step-by-step explanation:
The therapy least likely to be used for a child with cystic fibrosis who is hospitalized with a respiratory infection is C) Cough-suppressant medications.
Children with cystic fibrosis have excess mucus in their lungs, which can lead to respiratory infections. To treat these infections, therapies such as chest physiotherapy, intravenous antibiotics, and postural drainage are commonly used. These therapies help to clear the mucus, fight off infections, and improve lung function. However, cough-suppressant medications would be least likely to be used as they may hinder the clearance of mucus and prolong the infection.