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 hemophilia B patient needs a major surgery. Factor replacement should be done at what rate: 
Select and explain. 
A. 80-100 units/ kg every 12 hours, B. 80-100 units/kg every 24 hours, C. 60 units/kg every 12 hours, D. 80-100 units/kg every 6 hours
B: 80-100 units/kg every 24 hours
Answer: B: 80-100 units/kg every 24 hours 
Explanation: None