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: Pathology
The combination of rest pain, colour changes, oedema and hyperaesthesia 
Select and explain. 
A. Gangrene, B. Pregangrene, C. Necrosis, D. Vasculitis
B: Pregangrene
Answer: B: Pregangrene 
Explanation: None