This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oncology, Subject name: Medicine
Most common tumour of the posterior cranial fossa is - 
Select and explain. 
A. Glioma, B. Medulloblastoma, C. Meningioma, D. Oligodendroglioma
A: Glioma
Answer: A: Glioma 
Explanation: Gliomas account for 60% of brain tumours, with the aggressive glioblastoma multiforme (WHO grade IV) the most common glioma, followed by meningiomas (20%) and pituitary tumours (10%). Although the lower-grade gliomas (I and II) may be very indolent, with prognosis measured in terms of many years, these may transform to higher-grade disease at any time, with a resultant sharp decline in life expectancy Ref Harrison 20th edition pg2258