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: Anatomy
Cerebral aqueduct (Duct of Sylvius) - which is true: 
Select and explain. 
A. 3 cms in length, B. Connects III. ventricle to IV ventricle, C. Connects III. ventricle to IV ventricle, D. Connects two lateral ventricles
B: Connects III. ventricle to IV ventricle
Answer: B: Connects III. ventricle to IV ventricle 
Explanation: B i.e., Connects HI ventricle to IV ventricle- Rhomboid fossa or floor of 4th ventricle has abducent motor nucleus, dorsal motor nucleus of vagus, hypoglossal nucleus, and facial nucleus.- 4th ventricle communicates through cerebral aqueduct of sylvius with 3rd ventricle.