If You Hit Your Head During a Football Game,your Brain

Multiple Choice

If you hit your head during a football game,your brain fortunately provides some protection in the form of a fluid that creates a cushioning effect upon impact.Which fluid,produced by the glial cells,provides this cushioning effect

A)  blood-brain barrier 
B)  endorphins 
C)  cerebral spinal fluid 
D)  neurotransmitters