Which set of ordered pairs represents y as a function of x?
{(5,3), (2,8),(-5, -1),(4,7), (5,7)}
{(5,3), (2,8),(-5, -1),(4,7), (2, 1)}
{(5,3), (2,8),(-5, -1),(4,7),(-2,1)}
{(-5,3), (2,8), (-5, -1),(4,7), (2, 2)}
ASAP