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