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
MC comp. of talus is 
Select and explain. 
A. Avascular necrosis, B. Non union, C. Osteoahritis of ankle joint., D. Osteoahritis of subtalar joint.
A: Avascular necrosis
Answer: A: Avascular necrosis 
Explanation: A i.e Avascular necrosis