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
Retina is pa of ? 
Select and explain. 
A. CNS, B. PNA, C. ANS, D. None
A: CNS
Answer: A: CNS 
Explanation: Retina is a pa of CNS and develops from Neuroectoderm.