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
Main risk in fracture Scaphoid is: 
Select and explain. 
A. Non union, B. Malunion, C. Delayed union, D. Avascular necrosis
D: Avascular necrosis
Answer: D: Avascular necrosis 
Explanation: D i.e. Avascular necrosis