Determine which relation is a function.
{(-4, 3), (-2,3), (-1, 2), (2,5), (3, 2)}
{(-4,1), (-2, 3), (-2, 1), (-1, 5), (3, 2)}
{(-4,1), (-2, 3), (-1, 2), (3,5), (3, 2)}
{(-4, 1), (-2, 3), (-1, 1), (-1, 5), (3, 2)}​