This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'The earliest hematologic manifestation of megaloblastic anemia is \nSelect and explain. \nA. Increase in MCV, B. Hypersegmented polymorphs, C. Thrombocytopenia, D. Leukopenia', 'role': 'user'}, {'content': "Answer: B \nExplanation: Microcytic anemiaMacrocytic anemiaSideroblastic anemiaIron deficiency anemiaThalassemiaAnemia of chronic disease Liver disease Hypothyroidism Folic acid & vitamin B12 deficiency Cytotoxic drugs Megaloblastic anemiaTriad - Oval macrocyte , Howel Jolly bodies , Hypersegmented neutrophilsBone marrow - hypercellular bone marrow with megaloblast along with the presence of abnormal granulocytic precursors ( giant metamyelocyte & band forms ) and large megakaryocytes with bizarre multilobate nuclei Peripheral smear - pancytopenia with presence of macrocyte (MCV>100 fl) lacking central pallor ; large hypersegmented neutrophils ( >5 lobes )(Refer: Robbins & Cotran's - Pathologic Basis of Disease, SAE, 1st edition, Vol I-pg no: 643-648)", 'role': 'assistant'}]