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
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 - 
Select and explain. 
A. ESR estimation, B. Blood spherocyte estimation, C. Bone marrow aspiration, D. Hb-electrophoresis
D: Hb-electrophoresis
Answer: D: Hb-electrophoresis 
Explanation: Hemoglobin electrophoresis should always be the first investigation to include/exclude the diagnosis of thalassemia.
The level of normal adult hemoglobin HbA is markedly decreased with proportionate increase in HbA2 and HbF.

X-ray findings in thalassemia
1. Crew cut appearance
2. Hair on end appearance