This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Injuries Around the Thigh & Knee, Subject name: Orthopaedics
Anterior gliding of tibia on femur prevented by - 
Select and explain. 
A. Anterior cruciate ligament, B. Posterior cruciate ligament, C. Ligament of humprey, D. Ligament of wriesberg
A: Anterior cruciate ligament
Answer: A: Anterior cruciate ligament 
Explanation: Ans. is 'a' i.e., Anterior cruciate ligament * ACL provides antero-posterior stability and prevents anterior gliding of tibia on femur and prevents hyperextension.* PCL prevents posterior gliding (subluxation) of tibia over femur.