A Child with an Upper Respiratory Infection Caused by B

A child with an upper respiratory infection caused by B. pertussis is receiving erythromycin ethylsuccinate. After 2 days of treatment, the parent asks the nurse why the child's symptoms have not improved. Which response by the nurse is correct?

A) "Erythromycin eliminates the bacteria that causes the infection, but not the toxin that causes the symptoms."
B) "We may need to add penicillin or another antibiotic to increase the antimicrobial spectrum."
C) "We will need to review the culture sensitivity information to see whether a different antibiotic is indicated."
D) "Your child may have developed a suprainfection that we need to culture and treat."