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