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: Radiology
"Hair -on end" appearance is seen in: 
Select and explain. 
A. Thalassaemia, B. Sickle cell anemia, C. Hemoc hromatosis, D. Megaloblastic anemia
A: Thalassaemia
Answer: A: Thalassaemia 
Explanation: A i.e. Thalassemia