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
A 5 year old child is admitted with headache, vomiting and difficulty in walking. Physical findings include truncal ataxia, papilloedema and left lateral rectus palsy. No finger-to-nose ataxia could be detected on the left side or right side. The most likely diagnosis is – 
Select and explain. 
A. Dandy walker syndrome, B. Syringobulbia, C. Arnold-chiari malformation, D. Medulloblastoma
D: Medulloblastoma
Answer: D: Medulloblastoma 
Explanation: Congenital lesions would present Hydrocephalus since birth (for a & c)