Which set of ordered pairs represents a function?
o {(4,2), (-9, -2),(4, -1),(-8,8)}
o {(1,3), (4, 1), (3,0), (3,9)}
o {(0,6), (5, -9), (-7,8), (5,5)}
O {(2, -4), (-1, -5), (9,–8), (5,-4)}