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: Medicine
[{'content': 'HbH is characterized by \nSelect and explain. \nA. Deletion of three alpha genes, B. Deletion of three alpha and one beta gene, C. Deletion of two alpha and two beta genes, D. Deletion of four alpha genes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer- A. Deletion of three alpha genesHbH disease- Deletion of three alpha genes (--/-alpha)- hemolytic anemia', 'role': 'assistant'}]