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: Pathology
[{'content': 'The peripheral blood smear of a patient shows features of thalassemia, also presented with anemia. Family history is also +ve. The investigation was done to establish the diagnosis is - \nSelect and explain. \nA. ESR estimation, B. Blood spherocyte estimation, C. Bone marrow aspiration, D. Hb-electrophoresis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Hemoglobin electrophoresis should always be the first investigation to include/exclude the diagnosis of thalassemia.\nThe level of normal adult hemoglobin HbA is markedly decreased with proportionate increase in HbA2 and HbF.\n\nX-ray findings in thalassemia\n1. Crew cut appearance\n2. Hair on end appearance', 'role': 'assistant'}]