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
Central nervous system develops from ? 
Select and explain. 
A. Ectoderm, B. Endoderm, C. Mesoderm, D. All three germ layers
A: Ectoderm
Answer: A: Ectoderm 
Explanation: Nervous system develops from ectoderm (neuroectoderm).