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
[{'content': 'Most common site of osteochondritis dessicans - \nSelect and explain. \nA. Lateral part of the medial femoral condyle, B. Medial part of the medial femoral condyle, C. Lateral part of the lateral femoral condyle, D. Medial part of the lateral femoral condyle', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Osteochondritis dessicans involves lateral surface of medial femoral condyle.', 'role': 'assistant'}]