This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anemia, Subject name: Medicine
[{'content': "A 20 year old female presenting with anemia, mild jaundice for 2 years, peripheral smear showing spherocytes, the best investigation to be done is: \nSelect and explain. \nA. Reticulocyte count, B. Osmotic fragility test, C. Coomb's test, D. Bone marrow aspiration", 'role': 'user'}, {'content': "Answer: C \nExplanation: Spherocytes in adult patient indicates presence of autoimmune haemolytic anemia and hence Coomb's test should be performed. Presence of spherocytes alone is not sufficient for the diagnosis of hereditary spherocytosis. Evidence of hereditary nature of the disease is also required. Increased osmotic fragility merely reflects the presence of spherocytes and does not distinguish hereditary spherocytosis from other spherocytic hemolytic disorders.", 'role': 'assistant'}]