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
[{'content': 'MC comp. of talus is \nSelect and explain. \nA. Avascular necrosis, B. Non union, C. Osteoahritis of ankle joint., D. Osteoahritis of subtalar joint.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e Avascular necrosis', 'role': 'assistant'}]