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: Unknown
[{'content': 'Earliest manifestation of megaloblastic anemia is \nSelect and explain. \nA. Macrocytosis, B. Hypersegmented neutrophils, C. Basophilic stippling, D. Cabot ring', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Ref: Harrison 18/e p866, 17/e p645-646, Tejinder Singh 2/e p54-61)\n\xa0\n\n\n\n\nPeripheral blood picture\n\n\nBone marrow picture\n\n\n\n\n\nMacrocytosis (↑ MCV, MCH. Normal MCHC)\nPeripheral smear\n\n\xa0 \xa0 \xa0 \xa0 \xa0 \xa0Macroovalocytes\n\xa0 \xa0 \xa0 \xa0 \xa0 \xa0Few nucleated RBCs\n\xa0 \xa0 \xa0 \xa0 \xa0 \xa0Evidence of dyserythropoiesis like-\n\nBasophilic stippling\nCabot ring\nHowell- Jolly bodies\n\n\n↓ Hb\n↓ Hematocrit\nReticulocyte count – Normal or mild decrease\nWhite cells- Leucopenia\nHypersegmented neutrophils/ Macropolycytes- First manifestation \n↓ Platelets\nPancytopenia (10-20%)\n\n\xa0 \xa0Lab investigations:\n\nSerum iron, ferritin - ↑ in pure VitB12/ Folate defect\nSerum bilirubin & LDH ↑- due to hemolytic component\nSchillings test: Used to assess status of intrinsic factor (IF) & Vit B12 to distinguish pernicious anemia from other causes of Vit.B12\xa0 deficiency.\n\n\n\n\nModerate- marked hypercellularity\nErythroid hyperplasia\nM:E ratio reversal\nErthropoiesis- Megaloblastic\nGiant metamyelocytes\nMildly reduced megakaryocytes\nBM iron moderately increased in pure Vit B12/ Folate defects.', 'role': 'assistant'}]