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: Pathology
[{'content': 'HbH is associated with - \nSelect and explain. \nA. Deletion of 3 alpha genes, B. Deletion of 4 alpha genes, C. Deletion of 3 beta genes, D. Deletion of 4 beta genes', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]