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: Medicine
[{'content': 'A 23 year old female presenting with anemia, jaundice, for 2 years, peripheral smear showing spherocytes, the best investigation to be done - \nSelect and explain. \nA. Reticulocyte count, B. Osmotic fragility test, C. Coombs test, D. Bone marrow aspiration', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]