This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
[{'content': 'All are malignant tumors except - \nSelect and explain. \nA. Chloroma, B. Fibromatosis, C. Askins tumor, D. Liposarcoma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Fibromatosis are a group of fibroblastic proliferations having tendency to infiltrate. They are locally aggressive but do not metastasize. Basic Pathology, Robbins. Page no.: 793', 'role': 'assistant'}]