Which set of ordered pairs does NOT represent y as a function of x? O {(1,3), (2,6), (4,6), (7,8)}
O {(-3, 17), (4, -6), (2, 1), (0,4)}
O {(3, 2), (3, 4), (2,7), (8, 19)}
{(0.5, 0.25), (1, 3), (9, 10), (4, 2.5)}