[A]: Choroid plexus is one of two thin-walled greatly folded highly vascular regions in the inner wall of the brain through which ex- change of materials between blood and cerebrospinal fluid takes place.
[R]: The choroid plexuses (which form the blood-brain barrier) bar the entry of blood cells and large molecules into the cerea brospinal fluid.
A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false
