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