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: Surgery
Injury to which of the following ligament gives positive pivot shift test in knee? 
Select and explain. 
A. Posterior cruciate ligament, B. Anterior Cruciate ligament, C. Medial collateral ligament, D. Posterior elbow ligament
B: Anterior Cruciate ligament
Answer: B: Anterior Cruciate ligament 
Explanation: Pivot test is used to detect injury to anterior cruciate ligament. It is the most frequent and most severe ligament injury to the knee. It usually occur from a torsional stress coupled with deceleration injury. Other tests used to detect anterior cruciate ligament tear are anterior drawer test and the Lachman test. Posterior drawer test is a test to detect injury to posterior cruciate ligament. Medial collateral ligament tear is detected by valgus stress test at 30 degree knee flexion. Lateral collateral ligament tear is detected by varus stress test at 30 degree knee flexion. Ref: Taylor's Musculoskeletal Problems and Injuries: A Handbook edited by Robe B. Taylor, page 218.