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
Common posterior cranial fossa tumours include all of following except – 
Select and explain. 
A. Medulloblastoma, B. Oligodendroglioma, C. Ependymoma, D. Cystic astrocytoma
B: Oligodendroglioma
Answer: B: Oligodendroglioma 
Explanation: Oligodendrogliomas are uncommon tumours of childhood, occur predominently in the cerebral cortex and originate in white matter (Supratentorial).

Common childhood infratentorial post fossa tumors

Cerebellar astrocytoma (cystic astrocytoma)                        3) Brainstem glioma

2. MedullOblastoma (Primitive neuroectodennal tumor)                     4) Ependymoma