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