This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genitourinary radiology, Subject name: Radiology
[{'content': 'The ideal timing of radiotherapy for Wilms tumour after surgery is: \nSelect and explain. \nA. Within 10 days, B. Within 2 weeks, C. Within 3 weeks, D. Any time after surgery', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Radiotherapy is to be staed within 10 days. Delay in staing radiotherapy for Wilms tumour can result in an increase in relapse rate', 'role': 'assistant'}]