Question

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