Which of the Following Statements Are True of Fetal Hemoglobin

Multiple Choice

Which of the following statements are true of fetal hemoglobin?
I.Hemoglobin present in the fetus has a high affinity for oxygen.
II.HbF of normal-term infants has a P₅₀ of approximately 22 mm Hg.
III.A cyanotic newborn infant has a much lower arterial PO₂ than an equally cyanotic adult.
IV.By 6 months after birth, most HbF has been replaced with HbA.

A) I, II, III
B) II
C) II, III
D) I, II, III, IV