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
A low mean corpuscular volume with a normal red cell distribution width suggests - 
Select and explain. 
A. Iron deficiency anaemia, B. α Thalassaemia trait, C. Anaemia of chronic disease, D. Sideroblastic anaemia
B: α Thalassaemia trait
Answer: B: α Thalassaemia trait 
Explanation: None