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: Microbiology
[{'content': 'The mature cyst of Entamoeba histolytica differs from Entamoeba coli , in the following except - \nSelect and explain. \nA. Size is 6 to 15 microns, B. Nuclei are 1 to 4 in number, C. Karyosome is central in position, D. Chromatid bars seen', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]