Final answer:
The healthcare provider selected a specific antibiotic for the toddler with cystic fibrosis based on the sensitivity of the bacteria causing the pneumonia.
Step-by-step explanation:
The reason that the healthcare provider selected a specific antibiotic for the toddler with cystic fibrosis who has been hospitalized with bacterial pneumonia is sensitivity of the bacteria.
When determining the appropriate antibiotic, the healthcare provider will consider the susceptibility of the bacteria causing the infection. In this case, the nurse has concluded that the child has no known allergies, so the healthcare provider has selected an antibiotic based on the sensitivity of the bacteria causing the pneumonia.