This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'All are found is Posterior Mediastinum except: \nSelect and explain. \nA. Esophagus, B. Azygos vein, C. Thymus, D. Sympathetic Trunk', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. ThymusThe part behind the pericardium (enclosing heart) is called posterior mediastinum. Its contents are - Esophagus, thoracic duct, descending aorta, Sympathetic Trunk, Azygos vein, hemiazygos vein, accessory hemiazygos vein, vagus nerve, posterior mediastinal lymph nodes.', 'role': 'assistant'}]