A 72-year-old man with a 15-year history of hypertension presents to the emergency department with sudden-onset, severe, tearing substernal chest pain radiating to the interscapular region. He reports the pain began abruptly while he was walking. His current medications include lisinopril and amlodipine. Vital signs on presentation: BP 188/115 mmHg in the right arm and 152/98 mmHg in the left arm, HR 103/min, RR 24/min, temperature 37.1°C, SpO2 99% on room air. Physical examination reveals a new early diastolic murmur. Chest X-ray demonstrates a widened mediastinum and possible left pleural effusion. A 12-lead ECG shows normal sinus rhythm with no acute ST-segment changes. Which of the following is the most appropriate next step in diagnosis?

1. A)Transthoracic echocardiography
2. B)Cardiac catheterization with coronary angiography
3. C)CT angiography of the chest with IV contrastGABARITO
4. D)Transesophageal echocardiography
5. E)Chest X-ray with barium swallow