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': 'A child presents with ewings sarcoma. Histology shows it as one of the small round blue cell tumors. Which of the following gets accumulated in the cells of ewings sarcoma? \nSelect and explain. \nA. Fact, B. Proteoglycan, C. Glysaminoglycan, D. Glycogen', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Microscopy of ewings sarcoma shows, sheets of uniform small, round tumor cells with scanty clear cytoplasm, rich in glycogen.', 'role': 'assistant'}]