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: Surgery
Earliest symptom of Wilm's tumour 
Select and explain. 
A. Hematuria, B. Pyrexia, C. Abdominal mass, D. Metastases
C: Abdominal mass
Answer: C: Abdominal mass 
Explanation: None