Hello, I'd will be very glad to help you. :)
Your answer should be Nervous system.
Your answer would not be A, Circulation
because the eyes have nothing to do with
this. Your answer would not be B, Digestive
because Digestive would have to be around
your stomach and so on. And D, Skeletal, this
will also not be your answer because this is a
stystem the relates to your brain!
Hope this helps
-Jurgen :D