Which set of coordinates does not represent a function?
(0, 0)
(1, 2)
(2, 4)
(3,6)
(4,8)
(x, y)
(0,5)
(1, 10)
(1, 15)
(2, 20)
(2, 25)
(x, y)
(0, 17)
(1, -2)
(2,3)
(3, -6)
(4, 15)
(x, y)
(-2, -20)
(-1,-10)
(0,0)
(1, 10)
(2, 20)