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': 'Anterior cruciate ligament prevents - \nSelect and explain. \nA. Anterior dislocation of tibia, B. Posterior dislocation of tibia, C. Anterior dislocation of femur, D. Posterior dislocation of femur', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Anterior cruciate ligaments prevent anterior displacement of tibia over femur.', 'role': 'assistant'}]