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
Wilms tumor - most common presenting symptom 
Select and explain. 
A. Haematuria, B. Asymptomac abdominal mass, C. Abdominal pain, D. Headache
B: Asymptomac abdominal mass
Answer: B: Asymptomac abdominal mass 
Explanation: Wilm's tumor (Nephroblastoma) 

Most common malignant tumor of kidney,
80% of tumor present below 5 year of age.

Presentation 

Asymptomac abdominal mass (M. C.).
Haematuria (10-25%).
Hypertension (25%).
Abdominal pain (30%).
Fever (20%).