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
The oesophgus commences at the following level? 
Select and explain. 
A. Lower end of cricoid, B. C5 veebra, C. 10cm from incisor teeth, D. C7
A: Lower end of cricoid
Answer: A: Lower end of cricoid 
Explanation: A. i.e. Lower end of Cricoid