When auscultating the lungs, the nurse listens over symmetrical lung fields for which of the following?

Auscultation requires identifying adventitious sounds through the visceral pleura. Effective assessment depends on airflow turbulence generated by deep ventilation. Nurses evaluate bronchial, bronchovesicular, and vesicular sounds to detect pulmonary consolidation or airflow obstruction. Rationale: A. Pursed-lip breathing alters normal airflow dynamics and increases expiratory airway pressure. This technique is typically a compensatory mechanism for obstructive diseases like COPD and obscures the natural intensity of breath sounds required for accurate clinical auscultation. B. One full respiratory cycle through an open mouth reduces turbulence from the nasopharynx. This ensures maximum tidal volume enters the lower lobes, allowing the nurse to hear clear vesicular sounds and identify potential fine or coarse crackles. C. Nasal breathing increases resistance and creates extrapulmonary noise that mimics upper airway stridor. Auscultating only every 10 seconds is insufficient frequency to compare symmetrical segments effectively during a comprehensive physical examination of the posterior and anterior thorax. D. Exhaling through the nose limits the expiratory volume and duration audible through the stethoscope. Comparing symmetrical lung fields requires a consistent path for air to travel, and the mouth provides the least resistance for assessing lower airway patency.