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 structure lie at the level of arch of aoa? 
Select and explain. 
A. Left bronchus, B. Tracheal bifurcation, C. Ligament of teres, D. Bifurcation of pulmonary trunk
B: Tracheal bifurcation
Answer: B: Tracheal bifurcation 
Explanation: Tracheal bifurcation occur at the level of lower border of T4 veebrae, and the arch of aoa commences at the level of the sternal angle and ends at the lower border of T4. Structures located anteriorly and to the left of aoic arch are:Left lung and pleuraLeft vagus and left phrenic nerveLeft superior intercostal veinStructures located posteriorly and to the right of aoic arch are:Veebral columnEsophagusTracheaSuperior vena cavaStructures located above the arch of aoa:Brachiocephalic aeryLeft common carotid aeryLeft subclan aeryStructures located below the arch of aoa:Bifurcation of the pulmonary trunkLeft principal bronchus