This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Eye, Nose and Ear, Subject name: Anatomy
The optic cup is an evagination of which of the following? 
Select and explain. 
A. Telencephalon, B. Diencephalon, C. Mesencephalon, D. Metencephalon
B: Diencephalon
Answer: B: Diencephalon 
Explanation: The optic cup and its derivatives--the retina and optic nerve--develop from the diencephalon.