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
[{'content': 'Most common site of carcinoma 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: Answer is C (Lower 1/3rd) The lower third of the esophagus is the most common site of esophageal cancer and accounts for about 50% of all esophageal cancers. `About 15% of esophageal cancers occur in the upper third of esophagus (cervical esophagus), 35% in the middle third of esophagus and 50% in the lower third' - Harrison 16th/524 Site of esophageal cancer (All histological types) % of total Upper 1/3' 15% Middle 1/3rd 35% Lower 1/3'd 50% Note: The most common site of squamous cell (histological subtype) is middle 1/3 of esophagus The most common site of adenocarcinoma (histological subtype) is lower 1/3rd of esophaguse.", 'role': 'assistant'}]