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: Medicine
Red bone marrow is involved in erythropoiesis from 
Select and explain. 
A. 3 week to 3 months intra uterine, B. 3 months to 5 months Intrauterine, C. >5 months IU, D. > 5 months
C: >5 months IU
Answer: C: >5 months IU 
Explanation: Erythropoiesis:
Intra uterine Life:

3 wk to 3 month —> Yolk sac
3 month to 5 month —> Liver + spleen
> 5 Month —> Red bone marrow

 
Birth to 20 yrs —> Flat + long bones
 
> 20 yrs — Flat bone