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: Biochemistry
[{'content': 'In sickle cell anemia, replacement is - \nSelect and explain. \nA. Val by glu in β6, B. Glu by val in β6, C. Hist val β8, D. 6α', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In sickle cell anemia glutamate is replaced by valine at position 6 of β-chain.', 'role': 'assistant'}]