Which relation is NOT a function?
A. (0, 0), (1,3), (2, 3), (3,5), (4,3)
B. (-2, 0), (-1, 1), (0, 2), (0, 4),
(4, 5)
C. (2,0), (3, 2), (4,4), (5,2), (7,4)
D. (-1,4), (0,5), (2,6), (3,5),
(4,6)