A 32-year-old woman, 3 days post-C-section, presents with sudden onset dyspnea, pleuritic chest pain, and tachycardia. Her oxygen saturation is 92% on room air. ECG shows sinus tachycardia with S1Q3T3 pattern. Which of the following is the MOST appropriate initial diagnostic test to confirm the suspected diagnosis?
✓ Correct Answer: Option C
Given the high clinical suspicion for pulmonary embolism (post-C-section, classic symptoms, hypoxemia, ECG findings), CT pulmonary angiography (CTPA) is the gold standard for definitive diagnosis in hemodynamically stable patients.