Which of the following table of values represent a function?
A. (-1,5) (1,5) (4,5) (-4,5) (1,-5)
B. (1,0) (0,2) (5,-4) (-2,-1) (1,5)
C. (2,2) (3,3) (4,4) (5,5) (6,6)
D. (1,-4) (4,2) (-4,0) (0,3) (-4,-2)