This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: parasitology, Subject name: Microbiology
[{'content': 'Chromidial bars are absent in which stage of cysts in Entamoeba? \nSelect and explain. \nA. Uninucleate, B. Binucleate, C. Quadra nucleate, D. Octa nucleate', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In quadri nucleate stage, glycogen mass and chromidial bars are absent in cysts of Entamoeba Ref: Arora.Medical parasitology 4th ed pg. 38', 'role': 'assistant'}]