Which set of ordered pairs does not represent a function?
O {(4,4), (3, -8), (7,-6), (-5, -3)}
o {(-6,6), (8, 2), (8, -1), (3,3)}
o {(-4,-6), (-9, -7), (6, 7), (0, -6)}
o {(9, 5), (-5, -5), (0, 9), (8,3)}