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: Orthopaedics
Which type of injury causes more damage to the semi-lunar cartilage in the knee - 
Select and explain. 
A. Flexion and extension at the ankle, B. Rotation on a flexed knee, C. Rotation on an extended knee, D. Squatting position
B: Rotation on a flexed knee
Answer: B: Rotation on a flexed knee 
Explanation: Injuries of the menisci (semilunar cartilages) are common in men under the age of 45 years.
A tear is usually caused by a twisting force with the knee setniflexed or flexed.