(04.01 LC) PLZ ANSWER FAST!

Which set of ordered pairs represents a function?

{(0, 1), (1,3), (1,5), (2, 6)}

{(0, 0), (0, 2), (2, 2), (2,4)}

{(0, 0), (1, 2), (2, 4), (3,4)}

{(0, 1), (1, 2), (2, 3), (2,4)}