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': 'A common type of Ca in middle 3rd of the esophagus- \nSelect and explain. \nA. Adeno Carcinoma, B. Squamous Carcinoma, C. Adeno squamous Carcinoma, D. Leiomyosarcoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Esophageal carcinoma is of two common histological types -\n1. Squamous cell carcinoma\n\nMost common type worldwide.\nMost common type in India.\nOccurs in upper and middle 1/3rd of esophagus.\n\n2. Adenocarcinoma\n\nMost common type in the USA.\nLocated in the lower 1/3rd of esophagus.', 'role': 'assistant'}]