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: Biochemistry
Which among the following is the major hemoglobin found in fetus? 
Select and explain. 
A. Hb Gower-1, B. Hb F, C. Hb Gower-2, D. Hb Poland
B: Hb F
Answer: B: Hb F 
Explanation: Hb F (22) is the major hemoglobin of fetal life. After 34 to 36 weeks' gestation the percentage of Hb A rises, whereas that of Hb F decreases. Hb Gower-1 (22) is the major hemoglobin in embryos younger than 5 weeks' gestation. Hb Gower-2 (22) has been found in embryos with a gestational age as young as 4 weeks and is absent in embryos older than 13 weeks. Hb Poland (22) is found in young embryos. Ref: Palis J., Segel G.B. (2010). Chapter 6. Hematology of the Fetus and Newborn. In J.T. Prchal, K. Kaushansky, M.A. Lichtman, T.J. Kipps, U. Seligsohn (Eds), Williams Hematology, 8e.