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: Forensic Medicine
[{'content': 'Crural index is: \nSelect and explain. \nA. Length of tibia/femur x 100, B. Length of radius/humerus x 100, C. Length of fibula/tibia x 100, D. Length of radius/ulna x 100', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Length of tibia/femur x 100', 'role': 'assistant'}]