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: Medicine
TRALI occurs within how many hours of transfusion? 
Select and explain. 
A. 6 hours, B. 12 hours, C. 48 hours, D. 72 hours
A: 6 hours
Answer: A: 6 hours 
Explanation: TRALI is defined as Transfusion Associated Acute Lung injury (ALI) that occurs within 6 hours of transfusion with the majority of patients developing clinical features within 1-2 hours of transfusion (Usually 1 to 2 hours but up to 6 hours) Ref: Harrisons 20th edition