This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
A low mean corpuscular volume with a normal and cell distribution width suggests - 
Select and explain. 
A. Iron deficiency anemia, B. B thalassemia trait, C. Anemia of chronic disease, D. Sideroblastic anemia
B: B thalassemia trait
Answer: B: B thalassemia trait 
Explanation: In thalassemia MCV is decreased to 45-70fL &RBC count found to be increased or normal. The RBCs are microcytic and normochromic. Ref: Exam preparatory manual for UGs by Ramdas Nayak Page no:270 Ref Robbins 9/e pg 412