B

In α-thalassemia trait, synthesis of all non-α chains is intact, so HbA (α2β2), HbA2 (α2δ2), and HbF (α2γ2) proportions remain within the normal adult ranges; consequently hemoglobin electrophoresis or HPLC is typically normal, without elevation or depression of HbA2 or HbF [Sabath, 2003, PMID 12641611].