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: Medicine
The most common site of esophageal adenocarcinoma is: 
Select and explain. 
A. Upper 1/3rd, B. Middle 1/3rd, C. Lower 1/3rd, D. Upper 2/3rd
C: Lower 1/3rd
Answer: C: Lower 1/3rd 
Explanation: Answer is C (Lower 1/3rd) The most common site of adenocarcinoma esophagus is the lower 1/3rd of esophagus Esophageal Adenocarcinoma invariably arises from Barret's esophagus (Barret's ulcer) which is characteristically located in the distal esophagus around the gastroesophageal junction.