38. Binding of oxygen to hemoglobin may be affected by many effectors. Which of the following statements about these effects is correct? (A) Metabolically active tissues produce more acid and CO2, which can promote the binding of oxygen to hemoglobin. (B) NO. is a low-affinity ligand for hemoglobin so nitric oxide poisoning rarely occurs, (C) NO. irreversibly binds to the -SH functional group of Cys 93 in the β chain of hemoglobin resulting in inactivation of the hemoglobin. (D) The binding of 2,3-bisphosphoglycerate to hemoglobin can promote the release of oxygen from hemoglobin. (E) The reason why the adult-type and fetal-type hemoglobins have different O2 binding ability is because that the two proteins have different heme binding activities.