This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
[{'content': 'Length of CBD \nSelect and explain. \nA. 2.5 -5 cm, B. 5-7 cm, C. 7-11 cm, D. 10-15 cm', 'role': 'user'}, {'content': 'Answer: C \nExplanation: .', 'role': 'assistant'}]