This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Normal hematopoiesis, Subject name: Pediatrics
RBC Lifespan in preterm babies: 
Select and explain. 
A. < 40 days, B. 40-60 days, C. 75-90 days, D. 100-120 days
B: 40-60 days
Answer: B: 40-60 days 
Explanation: LIFE SPAN OF RBC: - Pre term neonates - 40-60 days - Term neonates - 90 days - Older children/ Adults - 120 days