This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
NOT a content of middle mediastinum: 
Select and explain. 
A. Ascending aoa, B. Oesophagus, C. Pulmonary trunk, D. Phrenic nerve
B: Oesophagus
Answer: B: Oesophagus 
Explanation: The esophagus is considered to be located in the superior and posterior mediastinum.