This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
Blood when stored at 4degC can be kept for- 
Select and explain. 
A. 7 days, B. 14 days, C. 21 days, D. 28 days
C: 21 days
Answer: C: 21 days 
Explanation: Typically, blood storage at 4 degrees C is sho term, which ranges from a few days to a few weeks. However, long-term storage usually involves blood being frozen, with a resultant loss in DNA yield. Refer robbins 9/e