This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
Outer blood retinal barrier is formed by 
Select and explain. 
A. Internal limiting mebrane, B. Endothelium, C. Retinal pigment epithelium, D. Ganglion cells
C: Retinal pigment epithelium
Answer: C: Retinal pigment epithelium 
Explanation: Outer blood retinal barrier is formed by retinal pigment epithelium Blood Retinal Barrier * Outer BRB: Formed by RPE * Inner BRB: Formed by endothelium of microvasculature