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: Radiology
[{'content': 'Spongy mass with sunburst calcification in center seen in CT is seen in: \nSelect and explain. \nA. Mucinous cystadenoma CA, B. Serous cystadenoma, C. Somatostationoma, D. Adenocarcinoma pancreas', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Serous cystadenoma', 'role': 'assistant'}]