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': 'Increased levels of haemoglobin A2 is characteristic of \nSelect and explain. \nA. Sickle cell trait, B. Beta-Thalassaemia trait, C. Glucose-6-phosphate dehydrogenase deficiency, D. Alpha-Thalassaemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]