This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
[{'content': 'Which of the following is most common hemoglobinopathy? \nSelect and explain. \nA. Thalassemia, B. Sickle cell anemia, C. Haemoglobin C, D. Christmas disease', 'role': 'user'}, {'content': 'Answer: B \nExplanation: *Any disease in which a mutation causes structurally abnormal hemoglobin is called "Hemoglobinopathy"Sickle cell disease is a common hereditary hemoglobinopathy caused by a point mutation in b-globin that promotes the polymerization of deoxygenated hemoglobin, leading to red cell distoion, hemolytic anemia, microvascular obstruction, and ischemic tissue damage.*Thalassemia is not considered as a type of hemoglobinopathy as the mutation causes absent globins, not abnormal globins. (Ref: Robbins 9/e p635)', 'role': 'assistant'}]