This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
Which of the following is the most common cause of congenital hydrocephalus? NOT RELATED-MEDICINE 
Select and explain. 
A. Craniosynostosis, B. Intra uterine meningitis, C. Aqueductal stenosis, D. Vein of Galen malformation
C: Aqueductal stenosis
Answer: C: Aqueductal stenosis 
Explanation: .