Final answer:
The best management for the patient's symptoms, which suggest a viral infection, is Ibuprofen, option C, to reduce fever and aches. Aspirin is not recommended for children, and antivirals or bronchodilators are not indicated without specific evidence or respiratory distress.
Step-by-step explanation:
The next best step in management for a 13-year-old female presenting with fever, chills, aching muscles, and mild cough without difficulty breathing, who is up to date on vaccines and has a negative rapid strep test, is Ibuprofen. This choice is indicated because Ibuprofen will help reduce the fever and alleviate muscle aches, which are symptoms suggestive of a viral infection like influenza.
Given the negative rapid strep test and the absence of bacterial signs such as exudative pharyngitis or severely swollen lymph nodes, it is unnecessary to start antibiotic therapy. In addition, Aspirin is generally avoided in children due to the risk of Reye's syndrome, and antiviral medications like Zanamivir and Amantadine are not typically first-line unless influenza is strongly suspected or confirmed. Albuterol is a bronchodilator meant for respiratory distress, which the patient does not exhibit.