This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
A 12 months old girl of Punjabi parents developed a pallor since 3 months of age. One unit of blood transfusion was done at 5 months of age. Now presents with pallor, on examination hepatosplenomegaly. Hematoglobin was 3.8 gin/d1, MCV=68, MCH=19. Peripheral smear showed schistocytes. one marrow examination show erythroid hyperplasia. Diagnosis is - 
Select and explain. 
A. Sickle cell anemia, B. Alpha-thalassemia, C. Beta-thalassemia (major), D. Glucose-6-phosphate dehydrogenase
C: Beta-thalassemia (major)
Answer: C: Beta-thalassemia (major) 
Explanation: None