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
A useful though temporary improvement in a patient's ischaemic foot can be attained by giving intravenously 
Select and explain. 
A. 10% Mannitol, B. 10% Dextrose, C. Dextran 40, D. Dextran 100
C: Dextran 40
Answer: C: Dextran 40 
Explanation: None