The nurse is assessing a client with a suspected pulmonary embolism (PE). Which symptom is most indicative of this condition?

The correct answer is C: 'Gradual onset of dyspnea.' While pulmonary embolism can present with various symptoms, the most common include sudden onset of dyspnea, chest pain (often pleuritic in nature), tachypnea, and tachycardia. Bilateral leg swelling is more commonly associated with conditions like deep vein thrombosis, not pulmonary embolism. Decreased breath sounds on auscultation may be seen in conditions like pneumothorax, not typically in pulmonary embolism. Therefore, the gradual onset of dyspnea is the most indicative symptom of pulmonary embolism in this scenario.