This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
[{'content': 'Length of adult trachea \nSelect and explain. \nA. 5-6 cm, B. 10-11 cm, C. 15-16cm, D. 20-21cm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Trachea is 10-15 cm length. <img src=" /> BD CHAURASIA\'S HUMAN ANATOMY VOLUE1 .6 TH EDITION. PAGE NO 281', 'role': 'assistant'}]