<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 27-year-old man comes to the physician because of pain and swelling in his right knee that began 3 days ago when he fell during football practice. He fell on his flexed right knee as he dove to complete a pass. He felt some mild knee pain but continued to practice. Over the next 2 days, the pain worsened and the knee began to swell. Today, the patient has an antalgic gait. Examination shows a swollen and tender right knee; flexion is limited by pain. The right knee is flexed and pressure is applied to proximal tibia; 8 mm of backward translation of the foreleg is observed. Which of the following is most likely injured?? A: Posterior cruciate ligament, B: Anterior cruciate ligament, C: Medial collateral ligament, D: Lateral collateral ligament, E: Lateral meniscus,  <response>: This is a clinical vignette describing a 27-year-old man with acute right knee pain and swelling after a football injury where he fell on his flexed right knee. The key findings are pain, swelling, antalgic gait, limited flexion due to pain, and 8mm of posterior tibial translation with applied pressure, indicating instability. The question asks which structure is most likely injured based on the history and physical exam findings. Posterior tibial translation with the knee flexed indicates injury to a stabilizing structure in the posterior compartment of the knee. The posterior cruciate ligament prevents posterior translation of the tibia on the femur, so injury to this ligament would allow pathologic posterior tibial translation.A: Posterior cruciate ligament 