Most common cause of hydrocephalus in children is –
Answer of this question is none because :-


MC cause of obstructive (non-communicating) hydrocephalus --> aqueductal stenosis.


MC cause of non-obstructive (communicating) hydrocephalus subarachanoid hemorrhage.
But, amongst the given options best answer is option 'a'.

"A common cause of acquired hydrocepahalus, is post inflammatory obstruction. Bacterial and tuberculous meningitis have a propensity to produce thick tenacious exudate that obstructs the basal cisterns ".
Post inflammatory obstruction
Buddchiary syndrome
Brain tumour
Perinatal injury