This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Wilms Tumor, Subject name: Pathology
[{'content': 'The most impoant determinant of prognosis of a patients with Wilms tumor is: \nSelect and explain. \nA. Stage of disease, B. Histology, C. Loss of chromosome 1p, D. Age of presentation', 'role': 'user'}, {'content': "Answer: B \nExplanation: Most impoant factor for prognosis of Wilm's tumor is Histology. Higher the degree of anaplasia - Poorer the prognosis. Presence of anaplasia associated with p53 gene mutation isresponsible for adverse prognosis.", 'role': 'assistant'}]