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
Which of the following structures is NOT found in both the superior and posterior mediastinum? 
Select and explain. 
A. Vagus nerve, B. Esophagus, C. Thoracic duct, D. Trachea
D: Trachea
Answer: D: Trachea 
Explanation: Since the trachea bifurcates at T4, it is not found in the posterior mediastinum