The nurse is aware that the patient seeking antibiotic treatment for pharyngitis will only receive the desired medication if the condition is caused by:

A. Bacteria: Antibiotics are specifically used to treat bacterial infections. In the case of pharyngitis, antibiotics are appropriate if the infection is caused by Streptococcus pyogenes (Group A strep), which can be confirmed via rapid strep test or throat culture. B. A fungal infection: Fungal infections are treated with antifungal medications, not antibiotics. Pharyngitis caused by fungi (e.g., Candida) is rare and requires different pharmacologic management. C. A virus: Viral pharyngitis is the most common cause of sore throat and does not respond to antibiotics. Treating viral infections with antibiotics contributes to antimicrobial resistance and unnecessary side effects. D. Protozoa: Protozoal infections typically affect the gastrointestinal or urogenital tract and are not a cause of pharyngitis. They are treated with antiparasitic agents, not antibiotics.