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