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