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': 'A low mean corpuscular volume with a normal red cell distribution width suggests - \nSelect and explain. \nA. Iron deficiency anaemia, B. α Thalassaemia trait, C. Anaemia of chronic disease, D. Sideroblastic anaemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]