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': 'Unlocking of knee is done by which muscle: September 2009, March 2013 (d, e, h) \nSelect and explain. \nA. Adductor magnus, B. Biceps femoris, C. Popliteus, D. Saorius', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Popliteus Popliteus muscle Origin: Lateral surface of lateral condyle of femur Inseion: Posterior surface of shaft of tibia above soleal line Nerve supply: Tibial nerve L4, 5; S1 Action: Flexes leg at knee joint; unlocks knee joint by lateral rotation of femur on tibia and slackens ligaments of joint', 'role': 'assistant'}]