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
Most common site for squamous cell ca. esophagus is 
Select and explain. 
A. Upper third, B. Middle third, C. Lower third, D. Gastro-esophageal junction
B: Middle third
Answer: B: Middle third 
Explanation: Ans. is 'b' i.e., Middle third Distribution of Squamous cell Ca Upper 1/3 10% Middle 1/3 60% Lower 1/3 30% (Values according to Sabiston 17/e, may be different in other texts but are approx. the same)