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
[{'content': 'Length of alimentary canal from oral cavity to gastro esophageal junction is- \nSelect and explain. \nA. l5cm, B. 25 cm, C. 30 cm, D. 40 cm', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]