This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hemoglobinopathies: Sickle cell anemia, Subject name: Pathology
[{'content': 'Sickle cell anemia is the clinical manifestation of homozygous genes for an abnormal haemoglobin molecule. The event responsible for the mutation in the b chain is: \nSelect and explain. \nA. Inseion, B. Deletion, C. Non-disjunction, D. Point mutation', 'role': 'user'}, {'content': 'Answer: D \nExplanation: - Sickle cell disease is a common hereditary hemoglobinopathy caused by point mutation resulting in replacement of Glutamic acid by Valine at 6th position of b-globin chain.', 'role': 'assistant'}]