This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lower limb, Subject name: Anatomy
[{'content': 'Locking muscle of Knee joint is \nSelect and explain. \nA. Vastus Lateralis, B. Vastus Medialis, C. Vastus Intermedius, D. Rectus Femoris', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Locking is a mechanism that allows the knee to remain in the position of full extension as in standing without much muscular effoLocking occurs as a result of medial rotation of the femur during the last stage of extension. Vastus medialis prevents lateral displacement of the patella.Reference: Chaurasia Volume II; 7th edition; Page no: 169', 'role': 'assistant'}]