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
An 18-yr-old boy was playing football when he suddenly twisted his knee on the ankle and he fell down. He got up after 10 minutes and again started playing, but the next day his knee was swollen and he could not move it. The most probable cause is - 
Select and explain. 
A. Medial meniscus tear, B. Anterior cruciate ligament tear, C. Medical collateral ligament injury, D. Posterior cruciate ligament injury
A: Medial meniscus tear
Answer: A: Medial meniscus tear 
Explanation: This boy has : -


History of twisting injury to the knee
Swelling appearing next day.


This is classical to the medial meniscal injury.
In ACL injury swelling appears immediately due to hemarthrosis.