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': 'Physiological locking is - \nSelect and explain. \nA. Internal rotation of femur over stabilized tibia, B. Internal rotation of tibia over stabilized femur, C. External rotation of tibia over stabilized tibia, D. External rotation of femur over stabilized tibia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: During last stages of extension, femur rotates medially on tibia due to quadriceps femoris to lock the knee joint.', 'role': 'assistant'}]