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: Ophthalmology
Retinal blood vessels are developed from – 
Select and explain. 
A. Surface ectoderm, B. Paraxial mesoderm, C. Endoderm, D. Neuro ectoderm
B: Paraxial mesoderm
Answer: B: Paraxial mesoderm 
Explanation: Blood vessels are derived from mesoderm.