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: Pediatrics
[{'content': 'Wilms tumor - most common presenting symptom \nSelect and explain. \nA. Haematuria, B. Asymptomac abdominal mass, C. Abdominal pain, D. Headache', 'role': 'user'}, {'content': "Answer: B \nExplanation: Wilm's tumor (Nephroblastoma) \n\nMost common malignant tumor of kidney,\n80% of tumor present below 5 year of age.\n\nPresentation \n\nAsymptomac abdominal mass (M. C.).\nHaematuria (10-25%).\nHypertension (25%).\nAbdominal pain (30%).\nFever (20%).", 'role': 'assistant'}]