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: Anatomy
[{'content': 'Length of inguinal canal - \nSelect and explain. \nA. 2.5 cm, B. 4 cm, C. 10 cm, D. 15 cm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]