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: Pathology
[{'content': 'M.C. site of Ca esophagus is ? \nSelect and explain. \nA. Middle 1/3rd, B. Upper 1/3rd, C. Lower 1/3rd, D. Lower end of esophagus', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Lower 1/3rdDistribution of esophageal Ca (Harrison 17th/e p. 571)Upper 3rd - 10%Middle 3'd 35%Lower 3rd --> 55%", 'role': 'assistant'}]