Fetal hemoglobin is different from adult hemoglobin because
A) It takes some time for the genes to mature B) The fetus doesn’t make enough of some kinds of amino acids C) The fetus’ hemoglobin must bind O2 more avidly than the mother’s hemoglobin D) The blood pH of the fetus is lower than the pH of the mother E) The fetus hemoglobin binds O2 at higher concentrations of O2 than the adult form