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: ENT
The commonest cranial nerve involved in acoustic neuroma is: 
Select and explain. 
A. IX, B. VI, C. VIII, D. X
C: VIII
Answer: C: VIII 
Explanation: As the eighth nerve schwannoma grows, it extends into the posterior fossa to occupy the angle between the cerebellum and pons (cerebellopontine angle). In this lateral position, it is so situated as to compress the seventh, fifth, and less often the ninth and tenth cranial nerves, which are implicated in various combinations. Later it displaces and compresses the pons and lateral medulla and obstructs the CSF circulation.