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: Surgery
3rd constriction of the oesophagus is at the level of- 
Select and explain. 
A. Left brunchus crossing the aorta, B. Where it pierces the diaphragm, C. Junction of the oesophagus and stomach, D. Cricopharynx
B: Where it pierces the diaphragm
Answer: B: Where it pierces the diaphragm 
Explanation: None