A patient with bronchitis is on an antibiotic regimen. Which sign indicates the treatment's effectiveness?

A. Persistent wheezing: Wheezing indicates continued airway inflammation or bronchospasm despite the administration of antimicrobial agents. It suggests that the underlying obstructive process or the inflammatory response to the pathogen remains active and unresolved. This finding would indicate a lack of clinical improvement. B. Reduction in sputum production: Successful eradication of the bacterial pathogen leads to a decrease in the inflammatory exudate within the bronchial tree. A quantitative and qualitative decline in sputum indicates that the infectious process is resolving and the bronchial mucosa is healing. This serves as a primary marker. C. Increased febrile episodes: A rising core body temperature suggests that the infection is worsening or the antibiotic is ineffective against the offending microorganism. Fever is a systemic inflammatory response to pyrogens, and its escalation is a sign of therapeutic failure. Effective treatment results in defervescence. D. Stable white blood cell count: In the presence of an active bacterial infection, one typically expects a leukocytosis with a left shift. A stable, elevated white blood cell count indicates that the immune system is still reacting to a significant microbial load. Effectiveness is shown by a downward trend.