This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oesophagus, Subject name: Surgery
M.C site of CA oesophagus is - 
Select and explain. 
A. Middle 1/3rd, B. Upper l/3rd, C. Lower l/3rd, D. Lower end of esophagus
A: Middle 1/3rd
Answer: A: Middle 1/3rd 
Explanation: Ans. is 'a' i.e., Middle l/3rd