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: Pathology
[{'content': 'Spherocytosis in blood smear seen in-a) Haemoglobin-Cb) Mechanical traumac) Hereditary spherocytosis d) Hereditary elliptosis \nSelect and explain. \nA. abc, B. acd, C. ac, D. bcd', 'role': 'user'}, {'content': "Answer: D \nExplanation: Spherocytes\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\n\nSpherocytes are small, spherical red blood cells (RBC).\nSpherocytes are approximately two-third the diameter of normal RBC.\nIn comparison to normal erythrocytes, they have a decreased surface area to volume ratio.\nThey are more densely hemoglobinized and lack a zone of central pallor (normal erythrocytes have central 1/3rd pallor)\n\nCauses of spherocytes \n\nImmunohemolytic anemia → Most common cause.\nDefect in red cell membrane.\nHereditary elliptocytosis\nBums\nG-6-PD deficiency\nWilson's disease\nHereditary spherocytosis\nHypophosphatemia\nToxins → Zinc toxicosis, Coral snake venom.\nTrauma to erythrocytes, e.g., in microangiopathic hemolytic anemia like DIC.\nParoxysmal cold hemoglobinuria.\n4-hydroxyphenolpyruvate hydroxylase deficiency.\nRhesus deficiency syndrome.", 'role': 'assistant'}]