This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Blood, Subject name: Medicine
[{'content': 'An 18-year-old man is recently diagnosed with beta-thalassemia minor. His hemoglobin is 10.5 g/dL, and he feels well. Which of the following findings is characteristic of this condition? \nSelect and explain. \nA. an increased amount of fetal hemoglobin (HbF) or hemoglobin A2 (HbA2), B. increased osmotic fragility of the red cells, C. absent bone marrow iron, D. increased macroglobulins in the serum', 'role': 'user'}, {'content': 'Answer: A \nExplanation: An increased amount of HbF or HbA2 would be expected. As beta-chains are decreased in beta-thalassemia, the excess alpha-chains combine with gamma- and delta-chains to make HbF and HbA2, respectively.', 'role': 'assistant'}]