A 50-year-old man presents with acute dysphagia and substernal chest pain after swallowing a large piece of meat. Vital signs: BP 128/82, HR 92, RR 18, Temp 37.2°C, SpO2 98% on room air. Chest X-ray shows a meat bolus lodged in the thoracic esophagus at the level of the sternal angle. No aspiration or perforation is noted. He denies recent weight loss or difficulty swallowing liquids. Compression by which anatomic structure most likely contributes to this normal site of esophageal narrowing?

1. A)Lower esophageal sphincter
2. B)Thoracic duct
3. C)Inferior vena cava
4. D)Cricopharyngeus muscle
5. E)Aortic arch and left main bronchusGABARITO